SIPRI’s conversion method (step by step)
Step 1 — Year-specific exchange rate
For each year t:
Iran’s military spending is taken in local currency (rial/toman) for year t.
It is converted to US dollars using the average exchange rate for year t (official/market rate depending on availability and SIPRI judgment).
This means:
1998 spending uses 1998 exchange rate
2012 spending uses 2012 exchange rate
2023 spending uses 2023 exchange rate

Step 2 — Inflation adjustment to constant 2023 USD
After conversion to current USD (year t), SIPRI then:
Deflates/inflates the USD series using US CPI / GDP deflator
Expresses everything in constant 2023 US dollars
So the formula conceptually is:

1) Rial collapse is reflected — year by year
Sharp devaluations (e.g. 2012, 2018, 2020) reduce the USD value of Iran’s spending in those years.
This is why Iran’s SIPRI series shows drops in USD terms even when rial spending rose domestically.

2) Constant USD ≠ purchasing power inside Iran
SIPRI’s constant-USD series measures internationally comparable value, not domestic real military capacity.
A rial collapse makes Iran look poorer in USD terms even if domestic military output did not fall proportionally.

This is a known limitation for sanctioned, inflationary economies.

But this means:

Iran’s military “output per dollar” is systematically understated relative to import-dependent countries like Saudi Arabia. This is methodologically acknowledged, not a mistake.

Each year uses its own exchange rate

for example in 2023:

Rial Value= 3079520546250000

Dollar Value: $7391

Average Exchange rate for the year : 416666 Rial=41667 Toman

Then values are inflation-adjusted to 2023 USD
Rial collapses are fully reflected
SIPRI numbers understate Iran’s real domestic military capacity
This means low expenditure in Iran does not mean low deterrence power

About 42% of Iran spending can be considered as knowledge generation investment 

About 10% of Saudi spending can be considered as knowledge generation investment 

Derivation logic 

Step 1 — Split total defense spending into buckets

For each country, decompose 100% of defense spending into:

1. Imports / foreign-executed services

2. Domestic sustainment (O&M without learning)

3. Domestic capability creation (KHG)

Saudi Arabia — derivation

Inputs

• Import share ≈ 75%

• Localized share ≈ 25% (by value)

• Of localized share, design authority fraction is limited.

Conservative assumptions (explicit)

• Imports (75%) → 0% KHG

• Localized (25%) splits into:

  • Assembly/MRO/licensed (≈60–80% of localized) → low learning

  • Design/R&D (≈20–40% of localized) → high learning

Calculation

• KHG from localized = 25% × (20–40%) = 5–10%

• Add small spillovers from training/ops learning = ~0–5%

Derived KHG (Saudi)

5% to 15%​

Why this is conservative: it assumes generous learning credit to licensed production and ops training.

Iran — derivation

Inputs

• Finished-system imports constrained by sanctions.

• Core programs (missiles/UAVs/EW) domestic, iterative, and production-centric.

Conservative assumptions (explicit)

• Imports/foreign services ≈ 10–20% → 0% KHG

• Domestic sustainment ≈ 30–40% → low learning

• Domestic capability creation ≈ 40–50% → high learning

Calculation

• KHG = 40–50% (direct domestic R&D + production learning)

• Ops/doctrine learning embedded in IRGC adds ~0–5%, but we keep it inside the same band.

Derived KHG (Iran)

35% to 50%​

Why this is conservative: it does not count PPP advantages or informal spillovers; it also caps ops learning.

References 

International Institute for Strategic Studies (IISS).

2022. Iran’s Ballistic Missile Capabilities: A Net Assessment. London: IISS.

(Used for: confirmation that Iran’s missile and UAV programs expanded despite sanctions and export controls.)

Stockholm International Peace Research Institute (SIPRI).

2024. Trends in International Arms Transfers, 2023. SIPRI Fact Sheet. Stockholm: SIPRI.

(Used for: Saudi Arabia’s arms-import dependence and supplier concentration.)

Stockholm International Peace Research Institute (SIPRI).

2025. Trends in International Arms Transfers, 2024. SIPRI Fact Sheet. Stockholm: SIPRI.

(Used for: persistence of Saudi import dependence despite recent reductions.)

General Authority for Military Industries (GAMI) (Saudi Arabia).

2025. Defense Localization Progress and Vision 2030 Targets. Riyadh: GAMI.

(Used for: confirmed localization level ~24.9% and stated >50% target by 2030.)

United States Department of the Treasury.

2025. Treasury Sanctions Procurement Network Supporting Iran’s Defense Industries Organization. Washington, DC: U.S. Department of the Treasury.

(Used for: evidence of active domestic defense production and procurement networks.)

Saudi Arabia’s Support to Proxy Groups – Financial and Material Estimates

Below is a comprehensive compilation of estimates from various sources on Saudi Arabia’s financial and material support to proxy groups. We break down the data by proxy group, providing annual and cumulative spending figures where available, source attributions (CONFIRMED by Saudi officials or records, ATTRIBUTED by third parties, or CONTRADICTED by Saudi denials), and the relevant time frames. A summary table is included for quick reference, followed by detailed sections for each group with source quotes and citations.

Summary Table of Saudi Proxy Support Estimates

Source: Compiled from declassified documents, intelligence leaks, think-tank analyses, media investigations, and official statements (detailed below with citations).

Al-Qaeda (incl. Afghan Jihad and Taliban)

Saudi Arabia’s support – both official and unofficial – to Al-Qaeda and its precursors can be traced back decades. Below are key estimates and reports:

• 1980s (Afghan Mujahideen): During the Soviet-Afghan war, Saudi Arabia matched U.S. contributions to the anti-Soviet mujahideen. CONFIRMED: Saudi official aid from 1979–1990 totaled nearly $4 billioncfr.org. (This does not include additional “unofficial” donations from Saudi charities, princes, and mosque collections.) This massive funding and arms pipeline, coordinated with the CIA and Pakistan’s ISI, nurtured the jihadist factions from which al-Qaeda later emergeden.wikipedia.org. Source: Saudi and U.S. records summarized by Ahmed Rashidcfr.org.

• 1990s (Taliban and bin Laden): After the Soviet withdrawal, Saudi Arabia turned its backing to the Taliban in Afghanistan, seeing it as a bulwark against Iranian influence. From 1996–1998, Riyadh was reportedly the Taliban’s main financial supporterhrw.org. ATTRIBUTED: Press accounts suggest Saudi aid to various Afghan factions reached $2 billion by the mid-1990shrw.org. Saudi intelligence chief Prince Turki al-Faisal met Taliban leaders; following these contacts, Saudi support included cash, fuel shipments and even arms deliveries (Saudi C-130 transport planes were seen unloading artillery and ammunition for the Taliban in 1996)hrw.org. Saudi also directly funded the Taliban’s repressive religious police agency, giving it a budget larger than any other Taliban ministryhrw.org.

  • Saudi officials denied direct links to al-Qaeda, but evidence shows substantial Saudi-sourced money reached bin Laden’s network. A controversial 2002 report by Jean-Charles Brisard claimed al-Qaeda received $300–$500 million in the decade prior to 9/11 by exploiting Saudi charities and donorseverycrsreport.com. ATTRIBUTED: This figure (roughly $30–50 million per year) was not officially confirmed and was later challenged in court as “untrue”everycrsreport.com, illustrating the difficulty of pinning down exact amounts. However, U.S. Treasury officials agreed that “Saudi Arabia today remains the location from which more money is going to terror groups … than from any other place in the world,” even after 9/11everycrsreport.com.

  • Contradictions: The 9/11 Commission found “no evidence that the Saudi government as an institution or senior officials funded Al-Qaeda,” but it noted Saudi Arabia was “a place where Al-Qaeda raised money directly from individuals and through charities,” including some with Saudi government sponsorshipeverycrsreport.com. Saudi authorities insist they never backed al-Qaeda; they cut off official Taliban aid after 1998’s embassy bombings and expelled bin Laden in the 1990shrw.orghrw.org. In fact, Saudi offered the Taliban $400 million for bin Laden’s extradition (a deal the Taliban refused)hrw.org – showing Saudi’s interest in curbing bin Laden by the late 1990s. This offer, reported by Western intelligence, underscores the murky duality: Saudi once bankrolled the Taliban, but later desperately sought to rein in Al-Qaeda’s leader.

• Early 2000s (Private Funding Networks): Even as Saudi officially fought al-Qaeda at home (especially after AQ attacks in the Kingdom in 2003), private Saudi financiers continued to play a major role in funding jihadist groups abroad. A 2009 secret memo by U.S. Secretary of State Hillary Clinton stated: “Donors in Saudi Arabia constitute the most significant source of funding to Sunni terrorist groups worldwide,” including al-Qaidatheguardian.com. Saudi individuals, often via charitable fronts, supplied money to al-Qaeda in the Arabian Peninsula (AQAP) and other offshoots. (For example, Gulf donors, many from Saudi, bankrolled AQAP and other militants in Yemen in the 2000s, though exact figures remain classified.)

• Iraq War (2003–2007): During the Iraqi insurgency, Saudi nationals funneled substantial funds to Sunni rebel groups, including Al-Qaeda in Iraq. ATTRIBUTED: The U.S. Iraq Study Group in 2006 identified Saudi private citizens as a key source of insurgent financingspokesman.com. Iraqi officials described “money pouring into Iraq from oil-rich Saudi Arabia” since 2003spokesman.com. In one case, $25 million in Saudi-sourced cash was delivered to a Sunni cleric to purchase weapons (including shoulder-fired missiles) for insurgentsspokesman.com. Overall Saudi contributions were described only as “millions of dollars” by the Associated Pressspokesman.com. Saudi Arabia’s government vehemently denied funding Iraqi fighters, calling such finance “unorganized acts” it would not permitspokesman.com. (This falls under CONTRADICTED – Saudi officials publicly rejected claims that Saudis bankrolled Iraq’s Al-Qaeda insurgencyspokesman.com.) Nonetheless, U.S. and Iraqi sources maintain that significant sums of Saudi private money (zakat donations, etc.) kept the Sunni insurgency alivespokesman.com, illustrating a pattern where Saudi donors acted as shadow financiers of al-Qaeda-linked campaigns beyond the Kingdom’s control.

Sources: Open-source investigations, leaked diplomatic cables, and official reportseverycrsreport.comspokesman.comtheguardian.com.

Jabhat al-Nusra (Hay’at Tahrir al-Sham, former al-Qaeda in Syria)

Saudi Arabia’s involvement in Syria’s civil war entailed backing various rebel factions, some of which were intertwined with or adjacent to al-Qaeda’s Syrian franchise, Jabhat al-Nusra (later rebranded as HTS). While Saudi did not openly acknowledge funding Nusra, multiple sources indicate that Saudi money—often via third parties or under the guise of supporting “moderate rebels”—reached Nusra by intent or accident:

• Gulf Funding Pipeline (2011–2014): Private donors from Saudi Arabia (and other Gulf states) generously bankrolled Syrian rebel groups, including Nusra. ATTRIBUTED: U.S. intelligence estimated that Gulf-based networks raised “hundreds of millions of dollars” for Syria’s rebels, with Saudis being the most generous contributorswashingtoninstitute.org. A senior U.S. official told The Washington Post in 2013 that these Gulf networks collected vast sums, ostensibly for humanitarian aid, but a portion was “deliberately obscured” and diverted to extremist factions like Jabhat al-Nusrawashingtonpost.com. He noted that social media campaigns were soliciting donations from within Saudi Arabia (despite Saudi laws against unapproved Syria fundraising)washingtonpost.com. In practice, wealthy Saudis sent money through Kuwait or other more permissive channels to reach Syrian jihadistswashingtoninstitute.org. This indirect financial flow on the order of hundreds of millions of USD significantly boosted Nusra’s war chest, even though the Saudi state formally outlawed Nusra (designating it a terrorist group in March 2014)washingtoninstitute.org.

• “Anything to Fight Assad” (2014 Biden Remarks): In a candid 2014 speech, U.S. Vice President Joe Biden admitted that America’s regional allies had, in their zeal to topple Syria’s Assad, “poured hundreds of millions of dollars and tens of thousands of tons of weapons into anyone who would fight Assad.” The result, Biden noted, was that “the people who were being supplied [with Saudi/UAE/Qatari arms] were al-Nusra, and al-Qaida and the extremist elements”voanews.com. This extraordinary statement (later partially walked back under diplomatic pressure) essentially confirms that Saudi Arabia and its Gulf partners funneled huge resources that ended up empowering Nusra and similar jihadist groups. Biden’s figure – “hundreds of millions” of dollars in funding – aligns with other reports from that period and is ATTRIBUTED to a high-ranking U.S. official sourcevoanews.com.

• Arms and Material Support: Beyond cash, Saudi Arabia supplied large quantities of weapons (often via Jordan or Turkey) to Syrian rebels. Some of this materiel was absorbed or captured by Nusra on the battlefield or shared through coalitions. For instance, in 2015 Saudi and Turkey jointly supported the Jaish al-Fatah (Army of Conquest) coalition in Idlib, which included Jabhat al-Nusra. Although exact spending is not public, analysts inferred tens of millions of dollars in arms and monthly stipends went into that alliance – effectively underwriting Nusra’s offensives indirectly. (This support is ATTRIBUTED based on investigative reporting and think-tank analyses; Saudi has never openly admitted funding Nusra.) Notably, Saudi officials tried to avoid direct support to al-Qaeda affiliates, preferring to fund other Islamist factions, but money and weapons proved fungible on Syria’s chaotic frontlines.

• Source Credibility and Saudi Stance: Saudi Arabia officially CONFIRMED that it banned any support to Nusra/HTS by mid-2014 (listing it as a terrorist entity alongside ISIS)washingtoninstitute.org. Saudi security forces also cracked down on domestic clerics raising funds for Nusra. However, the persistence of financing via private channels and the statements of U.S. officials indicate that ATTRIBUTED support continued at least in Nusra’s early years. There is no evidence of direct Saudi government funding to Nusra – indeed Saudi saw Nusra (an al-Qaeda franchise) as a future threat – but there is considerable evidence that Saudi-sourced money and arms reached Nusra through private donors and covert coalition operationswashingtonpost.comvoanews.com. Saudi has not contradicted reports of Gulf private fundraising for Nusra, but it emphasizes its own efforts to arm official Free Syrian Army units instead.

Sources: U.S. government statements and leaked speechesvoanews.com, Washington Institute and Post reportswashingtoninstitute.orgwashingtonpost.com, and regional expert analysis. (All point to large ATTRIBUTED sums in the hundreds of millions range flowing to Nusra and allied rebels circa 2012–2015.)

Daesh (ISIS)

Saudi Arabia’s relationship with Daesh (Islamic State) has been officially hostile – the Kingdom classifies ISIS as a terrorist organization and has fought its ideology. Still, questions have persisted about indirect Saudi contributions to ISIS’s rise. Key findings:

• No Official Saudi Funding – Confirmed Stance: Saudi government support to ISIS is non-existent by all credible accounts. In fact, “there is no credible evidence that the Saudi government is financially supporting ISIS. Riyadh views the group as a terrorist organization that poses a direct threat to the kingdom’s security.” This was the assessment of the Washington Institute in mid-2014washingtoninstitute.org, just as ISIS surged. The Saudi Interior Ministry formally banned ISIS (and similar groups) in March 2014, making any citizen support illegalwashingtoninstitute.org. Saudi officials have repeatedly CONTRADICTED and ridiculed claims that they fund ISIS; for example, a leaked 2014 email alleging Qatar and Saudi “providing clandestine… support to ISIL” was met with a Saudi statement that such claims “are preposterous and simply defy logic”voanews.com. The Saudi government’s position is that it actively fights ISIS, pointing to ISIS attacks and plots against Saudi targets as proof that the Kingdom is an ISIS enemywashingtoninstitute.org.

• Private Donors and “Leakage” (2012–2014): While ISIS derived most of its income from criminal enterprises (oil, extortion) after 2014, in its formative period the group did receive private donations from Gulf countries. U.S. officials indicated that “Saudi citizens continue to represent a significant funding source for Sunni groups operating in Syria, including ISIS and other groups”washingtoninstitute.org. Gulf charitable networks (often via Kuwait) channeled hundreds of millions of dollars into Syria’s conflict, and ISIS benefitted from that flowwashingtoninstitute.org. For example, by 2013-2014, fundraising campaigns on Twitter encouraged wealthy Saudis to send cash that ultimately reached ISIS or its allied factions, despite Saudi legal prohibitionswashingtoninstitute.orgwashingtonpost.com. This support is ATTRIBUTED to private actors: “There is support for ISIS in Saudi Arabia, and the group directly targets Saudis with fundraising campaigns,” wrote Lori Boghardt, a Gulf expert, noting that Saudi could do more to stem private money flowswashingtoninstitute.org. U.S. Treasury also hinted that some “politics, logistics, and limited capabilities” hampered Saudi enforcement against illicit ISIS financingwashingtoninstitute.org.

• Scale of Indirect Funding: Quantifying Saudi-sourced ISIS funding is tricky. One broad indicator: in 2013 a U.S. official told Washington Post that hundreds of millions had been raised by Gulf networks for Syria, though much went to humanitarian aid or other rebels – the share to ISIS or Nusra was deliberately concealedwashingtonpost.com. Another data point comes from 2014: U.S. Vice President Biden’s remarks implied that the money and arms Gulf states gave to Syrian rebels “ultimately helped militants linked to al-Qaida and ultimately IS”voanews.com. Thus, it is plausible that tens of millions of Saudi-sourced dollars ended up with ISIS by 2013-2014, before ISIS became a clear enemy. However, after mid-2014 when ISIS threatened Baghdad and expanded, Saudi Arabia joined the anti-ISIS coalition, and any earlier laissez-faire attitude toward private donations ceased.

• Accusations and Responses: The most specific allegation of Saudi state support came via a leaked Clinton email (Aug 2014) claiming Saudi’s government was giving “clandestine financial and logistic support to ISIL”voanews.com. This was never backed by public evidence and was strongly denied by both U.S. intelligence officials and Saudi authorities. Former U.S. Ambassador to Syria Robert Ford said he “never saw intelligence” of Saudi government aiding ISISvoanews.com. The consensus view is that Saudi as a state did not fund ISIS – if anything, Saudi Arabia was bombing ISIS by late 2014. Thus that claim remains UNCONFIRMED and officially refuted (CONTRADICTED)voanews.com.

In summary, Saudi Arabia’s support to ISIS was not official. Instead, ATTRIBUTED support came from private Saudi donors in ISIS’s early rise, likely amounting to a share of the “hundreds of millions” that Gulf networks poured into Syriawashingtoninstitute.org. Saudi authorities acknowledge the challenge of stopping wealthy sympathizers (e.g. cash couriers circumventing banking oversight)washingtoninstitute.orgwashingtoninstitute.org, but they insist they have taken steps (arrests, new laws) to stifle ISIS funding from their soil.

Sources: Washington Institute briefwashingtoninstitute.orgwashingtoninstitute.org; Voice of America reporting on leaked email and responsesvoanews.comvoanews.com; U.S. Treasury and State Department statements.

Yemeni Forces (Pro-Government Militias and Military)

Saudi Arabia’s largest recent proxy expenditure has been in Yemen’s civil war (2015–present). Since 2015, Saudi leads a coalition to restore the Yemeni government, providing vast financial and material support to Yemeni forces (army units, tribal militias, and Southern fighters) fighting the Houthi rebels. Key estimates include:

• Pre-War Aid (2012–2014): After Yemen’s 2011 uprising, Saudi Arabia bankrolled the transition under President Hadi. ATTRIBUTED: An estimated $4 billion in Saudi aid flowed to Yemen’s new government between 2012 and 2014nationalinterest.org. This included direct cash infusions, subsidized oil products, and development assistance to stabilize Yemen’s fragile economy. (For context, Saudi publicly pledged $3.25 billion in aid in 2012; by 2014 much of this had been delivered.) This financial lifeline was CONFIRMED by Saudi officials in general (though exact totals vary) and underscored Yemen’s dependence on Riyadh’s patronage prior to the war.

• War Expenditures (2015 onward): The Saudi-led intervention launched in March 2015 rapidly became a massive financial commitment. While Saudi does not publish the costs, outside analyses have produced striking figures:

  • In early 2015, based on the scale of air operations, military analysts at IISS estimated Saudi’s air campaign might cost around $175 million per month (using 100 fighter jets)reuters.com. A prolonged 5–6 month air war was thus projected at $1 billion+ for munitions and operationsreuters.com. This was considered easily affordable relative to Saudi’s $80+ billion defense budgetreuters.com. Source: Reuters reporting, citing UK MoD benchmarks (ATTRIBUTED)reuters.com.

  • By the end of 2015, costs escalated with ground operations and sustained bombing. David Ottaway of the Wilson Center assessed that the Saudi-led coalition was spending about $200 million per day on the Yemen waren.wikipedia.org. This eye-popping figure (roughly $6 billion per month) likely includes broader coalition activity and is at the high end of estimates. It suggests that by late 2015 Saudi Arabia was shouldering the lion’s share of a burn rate that could exceed $70 billion per year if accurate. Ottaway noted Saudi covers “most of the funding” of the coalitionen.wikipedia.org. (This number is ATTRIBUTED and speculative, but it underscores the war’s extreme cost.)

  • Cumulative Spending: By March 2018 (three years into the war), experts estimated the war had cost Saudi Arabia “upwards of $100 billion”nationalinterest.org. This figure, cited by The National Interest and others, accounts for military operations, weapons procurement, and funding of Yemeni proxy forces. It implies an average of roughly $30–$40 billion per year. Saudi sources have not confirmed this sum, but it has been widely quoted in think-tank circles (ATTRIBUTED)nationalinterest.org. More recently, some analyses put the total Saudi cost even higher, noting that as the war dragged into its seventh year, expenses for air operations, contractor support, and reconstruction of liberated areas continued to mount (some estimates in media talk of $120–$150 billion by 2022, though not officially verified).

• Support to Yemeni Proxy Forces: Instead of committing large numbers of their own ground troops, the Saudis (and Emiratis) finance, train, and equip local Yemeni fighters:

  • Salaries & Training: Saudi Arabia pays the salaries of tens of thousands of Yemeni soldiers and militia members. By 2016–2017, reports indicated Riyadh was covering payrolls for the internationally recognized government’s army and allied tribal fighters (exact annual figures are opaque, but likely in the hundreds of millions of dollars per year for salaries alone). CONFIRMED: The Saudi-led coalition openly announced programs to train Yemeni army recruits, and Saudi officials have acknowledged funding auxiliary forces (e.g. the “Giants Brigade” militia).

  • Arms & Equipment: The Kingdom has supplied armored vehicles, small arms, ammunition, and even heavy weapons to Yemeni pro-government forces. For example, in 2015 Saudi gave the Yemeni army dozens of tanks and APCs and forged an alliance with southern separatist militias by arming them. While no public price tag exists, these transfers are part of the war cost. One can infer billions of dollars worth of Saudi-bought weaponry ended up in Yemeni hands (since Saudi replenished its stocks with big arms imports). ATTRIBUTED: The Jamestown Foundation observes that “Saudi Arabia and its allies are training and arming a mix of militias… The groups are being used as proxies in the land war against the Houthis.”jamestown.org This clearly indicates material support in terms of arms and training, corroborating on-the-ground reports.

  • Humanitarian & Economic Aid: In parallel, Saudi Arabia provided large aid packages to the areas under its allies’ control – partly to win hearts and minds, partly to prop up the Yemeni government. CONFIRMED: In 2018, Saudi and the UAE announced a joint $500 million aid initiative for Yemen; by then they touted that $18 billion had been contributed in humanitarian aid by the coalition since 2015reliefweb.int. As of 2022, the King Salman Relief Center reported Saudi’s total aid to Yemen at $12 billion+ (humanitarian, development, and central bank deposits)ksrelief.org. While this aid is not military spending, it illustrates the cumulative financial commitment beyond the battlefield. It also indirectly supports proxy forces by stabilizing the areas they hold (paying government salaries, fueling power plants, etc.).

• Attribution and Denials: Unlike other proxy cases, Saudi Arabia is quite open about much of its spending in Yemen – proudly announcing aid sums and occasionally alluding to military support. Thus, many figures here are CONFIRMED or Officially Acknowledged (e.g. the humanitarian aid billionsreliefweb.int). The military cost estimates, however, remain ATTRIBUTED to analysts; Saudi officials do not publish war expenditures or admit the full bill. There is no contradiction from Saudi on whether they fund Yemeni armed forces – they openly do so, as that is the core of their intervention strategy. The only area of denial is regarding excessive civilian harm or any support to groups like al-Qaeda in Yemen. (Notably, some reports accused Saudi of tacitly cooperating with Sunni Islamist militias against the Houthis, including Islah party militias – but no clear financial figures on that exist.)

In short, Saudi Arabia’s support to Yemeni proxy forces is on a scale dwarfing all other cases in this report. From billions in direct aid to the government (confirmed)ksrelief.org, to tens of billions in military spending (attributed)nationalinterest.org, Riyadh’s investment (2015–2021) likely exceeded $100 billion. This has funded an army-by-proxy of local fighters and sustained a grinding war effort that Saudi leaders, by their own admission, deemed crucial against what they view as Iran-backed rebels.

Sources: Reuters analysis of war costreuters.com, Wilson Center/Ottaway estimateen.wikipedia.org, National Interest (Yoel Guzansky)nationalinterest.org, official Saudi aid statementsreliefweb.int, Jamestown Foundation reportjamestown.org.

Other Armed Proxy Groups (Notably: Taliban, Hamas, etc.)

Beyond the groups above, Saudi Arabia has at times supported other non-state actors for strategic reasons. Below are a few notable instances, with available estimates:

• Afghan Taliban (mid-1990s): As mentioned under Al-Qaeda, Saudi Arabia was a primary backer of the Taliban regime until 1998. ATTRIBUTED: Saudi assistance (financial and in-kind) to the Taliban from 1994–1998 has been estimated in the hundreds of millions. For example, Saudi provided the Taliban with free or discounted oil worth $ tens of millions per year, cash infusions for their budget, and projects like building religious schools. While exact annual figures aren’t published, the scale is indicated by reports that Riyadh gave $150 million even to the rival Yemen-recognized government of Burhanuddin Rabbani in 1993-94, before switching to full Taliban supporthrw.org. Once the Taliban took Kabul in 1996, Saudi intelligence began direct funding. CONFIRMED by multiple accounts: Prince Turki’s visits in 1996 led to Saudi Arabia becoming “the Taliban’s main financial supporter.”hrw.org Western intelligence even noted that after bin Laden’s attacks on U.S. embassies, Saudi tried to buy bin Laden back: they offered $400 million to the Taliban to hand him overhrw.org – a striking figure that, while it did not materialize, shows the magnitude of funds in play. Saudi cut ties in 1998–1999, and CONFIRMED it severed official aid after Taliban refused to expel bin Ladenhrw.org. Nonetheless, private Saudi donations continued flowing to the Taliban (ATTRIBUTED via charities and sympathetic princes) even after official relations frozehrw.org. Overall, Saudi financial patronage was pivotal in the Taliban’s rise; one academic study cited total Saudi aid to Afghan factions (Taliban and others) at $2–3 billion over the 1980s–90shrw.org.

• Palestinian Militias (Hamas and others): Saudi Arabia has long funded Palestinian causes, though it insists this is humanitarian or political support, not terrorism. Saudi committees in early 2000s did send money that reached families of suicide bombers and members of groups like Hamas – a practice heavily criticized by the U.S. and Israel. CONFIRMED: A Saudi government report in 2002 stated total Saudi government and private aid to Palestinians was $2.61 billion historicallyeverycrsreport.com. In the 2000–2003 Intifada period, Riyadh gave about $80–$100 million per year officially to the Palestinian Authorityeverycrsreport.com. However, ATTRIBUTED: Israeli sources alleged some Saudi funds went indirectly to Hamas (via charities). Saudi Arabia denies funding Hamas’ military activities – it designates Hamas as a legitimate resistance (at least historically) but not a proxy. U.S. Treasury designations in 2004 identified Saudi charities like al-Haramain as conduits that sent money to al-Qaeda and Hamas; these were shut under U.S. pressure. Thus, while not a classic “proxy” case, it’s worth noting Saudi’s CONFIRMED $100M/year aid to Palestinian entities and ATTRIBUTED support to groups like Hamas or Fatah factions (Riyadh channeled money to Fatah-aligned militias during the Fatah-Hamas split, reportedly tens of millions, to counter Iran’s influence on Hamas – though exact sums were secret).

• Lebanese and Other Sunni Militias: To counter Iran’s allies, Saudi Arabia in the 2000s and 2010s has backed Sunni factions elsewhere. For instance, Saudi money allegedly supported Sunni politicians and its funds may have reached the militant group Fatah al-Islam in Lebanon (this was rumored during the 2007 conflict at Nahr al-Bared, though never officially confirmed). Saudi also gave $3 billion to Lebanon’s army in 2013 (though later frozen) – showing a willingness to fund armed groups abroad. In Iraq (2005–2007), as noted earlier, Saudi private donors sent millions to Sunni insurgents (some aligned with al-Qaeda in Iraq). In Syria (non-Nusra rebels), Saudi spent heavily on factions like Jaysh al-Islam (led by Zahran Alloush) and others, possibly over $1–2 billion in arms and funds through the war – though precise breakdowns are scarce. Vice PM of Syria’s opposition once said Saudi provided salaries to rebel fighters in certain fronts, indicating an organized proxy support. These are ATTRIBUTED via media and think-tank reports since Saudi does not detail such spending.

• Ideological Financing: A broader category of support is Saudi’s funding of madrasas and “charities” that spread its ideology (Wahhabism) across the Muslim world. Confirmed by Saudi officials: Riyadh spent $s of billions since the 1980s building religious schools and mosques from Pakistan to Africa. While not arming a specific militia, this created an enabling environment for groups like the Taliban and others to recruit. A Cato Institute commentary (2001) noted: “The Saudi government has funded dubious schools and ‘charities’… hotbeds of anti-Western indoctrination. Graduates… are frequently recruits for Bin Laden’s Al-Qaeda network as well as other extremist groups.”cato.orgcato.org. This long-term investment (estimates range up to $100 billion over decades on global Islamic activities) is CONFIRMED Saudi policy, though they deny it was intended to spawn terrorism.

Attribution: Saudi Arabia usually denies direct support to any group officially deemed terrorist by the West. Yet, evidence from declassified cables (WikiLeaks), such as Clinton’s 2009 memo, explicitly ties Saudi donors to groups like Lashkar-e-Taiba (LeT) and the Talibantheguardian.com. Clinton wrote: “Saudi Arabia remains a critical financial support base for al-Qaida, the Taliban, LeT and other terrorist groups… Donors in Saudi Arabia constitute the most significant source of funding to Sunni terrorist groups worldwide.”theguardian.comtheguardian.com. This is a strong ATTRIBUTED statement from the highest levels of the U.S. government, implicating Saudi (primarily private sector) in funding a gamut of proxies beyond those listed.

In response, Saudi contradicts none of the historical aid to mujahideen or Taliban (those were state decisions), but it does reject being labeled a sponsor of terrorism in the present. The Kingdom points to its internal crackdown (post-2003) and cooperation with the U.S. to shut down terror financing. The tug-of-war between U.S. allegations and Saudi rebuttals is epitomized by a 2010 Guardian report: Saudi is described as “the world’s largest source of funds for Islamist militant groups”, yet Saudi officials are “reluctant to stem the flow of money”theguardian.comtheguardian.com. Saudi’s official stance is that any such funding is done by rogue individuals, not with state approval.

In Conclusion: Saudi Arabia’s financial/material support to proxy groups has varied widely by group and era:

• It is CONFIRMED that Saudi statesmen bankrolled anti-Soviet fighters ($3–4 billion) and pro-Saudi regimes or forces (e.g. billions to Yemen, Palestine).

• Many other figures are ATTRIBUTED through intelligence or investigative reports: e.g. hundreds of millions to Syrian rebels (some extremist), and vast war expenditures in Yemen (~$100 billion).

• Saudi Arabia often CONTRADICTS claims of supporting groups like al-Qaeda or ISIS, and indeed no official support to those groups is documented – only indirect or unofficial streams that outside observers have identified.

Each of these estimates comes with uncertainties, but together they paint a picture: tens of billions of dollars have been spent by Saudi Arabia in proxy conflicts across the Middle East and beyond, making it one of the principal patrons of armed non-state actors (especially those aligned with Sunni interests) over the past several decadescato.orgtheguardian.com. The exact amounts and effectiveness of this spending continue to be debated, but the sourced figures above offer a grounded approximation of Saudi Arabia’s proxy war bankroll.

Sources Cited: We have drawn on intelligence leakstheguardian.com, official U.S. and Saudi statementseverycrsreport.comksrelief.org, think-tank analysesnationalinterest.org, media investigations (AP, Reuters, Guardian)spokesman.comtheguardian.com, and academic research to compile these estimates. Each estimate is annotated with its attribution and credibility in the context provided above.