Although White House officials said Thursday that Mr. Biden had not made a final decision, several officials said they expected him to give his final approval soon. The timing is awkward for Mr. Biden, who heads to Europe for a NATO meeting in Vilnius, Lithuania, next week. It also comes as the US moves to destroy other dangerous weapons – the last of its once vast arsenal of chemical weapons.
Most of Washington’s closest allies, including Britain, Germany and France, signed the United Nations Convention on Cluster Munitions in 2008. The United States, Russia and Ukraine have never signed the treaty, arguing that there are circumstances in which the weapons must be . used, despite the potential for severe civilian casualties.
Mr. Biden was convinced, officials said, after the Pentagon argued that they would provide Ukraine with an “improved” version of the weapon, which has a “degradation” of about 2 percent of all shots fired.
Russia, officials noted, used its cluster munitions in Ukraine for much of the war, with a decline rate of 40 percent or more, creating a far greater danger. The Ukrainians also used cluster munitions, although their stockpile is a fraction of Washington’s.
Many bomb experts say the failure rates of US cluster munitions are likely much higher than Pentagon estimates.
“If they land in water, soft ground like plowed fields and muddy areas, that can definitely affect reliability, causing higher wastage,” said Al Vosburgh, a retired Army colonel trained in bomb disposal who runs a humanitarian mine action nonprofit.
On Thursday morning, Human Rights Watch published a long report on the use of cluster munitions in Ukraine. “Scratches used by Russia and Ukraine are killing civilians now and will continue to do so for many years to come,” Mary Wareham, the organization’s acting weapons director, wrote. “Both sides should immediately stop using them and not try to acquire more of these indiscriminate weapons.” In fact, the Ukrainians have been using the weapons since early in the war, often on their own territory.