“The Department of Defense has determined that cluster munitions remain a vital military capability in the tougher warfighting environment ahead of us, while still a relatively safe one,” Pentagon spokesman Tom Crosson told me. “This was a hard choice, not one the department made lightly,”

The Pentagon’s senior leadership determined that ending the use of cluster munitions currently in U.S. stocks would create a capability gap for U.S. forces, adding risk in a conflict and weakening deterrence, Crosson said. But he added that the new policy includes a commitment to acquiring safer and more reliable cluster munitions, which was one goal of the Bush administration policy.

The United States is not a party to the 2008 Convention on Cluster Munitions, which bans all use, purchase or transfer of the weapons. The pact includes 102 nations as full parties and 17 as signatories. But the U.S. military has not used cluster bombs in large amounts since 2003, at the start of the Iraq War. There is some evidence limited use occurred in 2009 in Yemen.