Cluster Weapons U.S. Is Sending Ukraine Often Fail to Detonate

When the White House announced on Friday that it would agree to supply Ukraine with cluster munitions, it came after assurances from Pentagon officials that the weapons had been improved to minimize the danger to civilians.

The weapons, which have been shunned by many countries, drop small grenades that are built to destroy armored vehicles and troops in the open, but also often fail to immediately explode. Years or even decades later, they can kill adults and children who stumble on them.

The Pentagon said the weapons they would send to Ukraine had a failure rate of 2.35 percent or less, far better than the usual rate that is common for cluster weapons.

But the Pentagon’s own statements indicate that the cluster munitions in question contain older grenades known to have a failure rate of 14 percent or more.

They are 155-millimeter artillery shells that each can fly about 20 miles before breaking open midair and releasing 72 small grenades that typically explode on impact along the perimeter of an oval-shaped area larger than a football field.

Pentagon officials have said the shells they will send to Ukraine are an improved version of a type used in 1991’s Operation Desert Storm. But the reality is slightly more complicated. The shells being sent to Kyiv can fly farther than the earlier versions, but they contain the same grenades, which had dud rates the Pentagon has characterized as unacceptably high.

Al Vosburgh, a retired Army colonel trained in bomb disposal, said that once the shooting stops in Ukraine, it will take a massive educational campaign to warn civilians of the risks of unexploded grenades before they can safely return home.

The biggest operational concern for Ukrainian soldiers, he said, is that the dud grenades left on the ground by these shells cannot safely be moved by hand.

“You have to take great pains to clear those because you’re not supposed to move them,” said Mr. Vosburgh, who now runs the mine-clearance nonprofit group Golden West. “In an area that’s been saturated with them, you’re going to find a lot of duds, so it’s a slow and methodical process to dispose of them.”

But Biden administration officials said they had little choice but to provide cluster munitions despite their lasting danger as Ukraine burns through artillery rounds and tries to make gains in a grueling counteroffensive against Russian troops.

Jake Sullivan, the president’s national security adviser, defended the use of the weapons and said that Russia had been using them since the beginning of the war. Ukraine has also used Russian-made cluster munitions, and had repeatedly asked for American-made ones, knowing the United States maintains large reserves.

“Ukraine would not be using these munitions in some foreign land,” Mr. Sullivan said. “This is their country they’re defending. These are their citizens they’re protecting and they are motivated to use any weapon system they have in a way that minimizes risks to those citizens.”

Weapons of this type are banned by more than 100 countries, in part because more than half of those killed or injured by them are civilians. Neither the United States nor Russia or Ukraine has signed the treaty prohibiting their stockpiling or use.

Analysts say that as many as 40 percent of the bomblets from Russia’s cluster munitions have resulted in duds.

Brig. Gen. Patrick S. Ryder, a Pentagon spokesman, said the Defense Department does comprehensive testing of the cluster munitions in its stocks, and “the ones that we are providing to Ukraine are tested at under a 2.35 percent dud rate.”

Such a rate would mean that for every two shells fired, about three unexploded grenades would be left scattered on the target area. But the dud rate for these grenades has been observed at rates seven times higher in combat.

In a briefing to reporters on Friday, Colin H. Kahl, the under secretary of defense for policy, said that the shells being sent to Ukraine had been tested five times between 1998 and 2020.

“The tests themselves are classified,” he said, adding that he has “high confidence” in their results.

The timing of those tests matches the availability of a shell called M864 whose production ceased in 1996, and an Army official confirmed on Friday that the last cluster artillery shell live-fire reliability tests the service had done were on M864 shells at Yuma, Ariz., in 2020.

The dud rate numbers offered by Pentagon officials vary greatly from what bomb disposal technicians and civilian deminers find in the field in post-conflict areas, including from the M864 projectile.

U.S. military bomb-disposal specialists are trained to exercise extreme caution in places where cluster weapons have been used, and to expect that about 20 percent of all submunitions, regardless of the country of origin, will fail to explode.

The projectiles being sent to Ukraine are commonly referred to by the name given to those small grenades: dual-purpose improved conventional munitions, or D.P.I.C.M. — and pronounced by some officials as dee-PICK-’ems.

The grenades, which are about the size and shape of a D-cell battery, are stabilized in flight by a nylon ribbon streaming from the top. Weighing less than half a pound each, they contain an explosive warhead that will fire a jet of molten metal downward capable of penetrating two and a half inches of armor plate.

The detonation also causes the grenade’s steel casing to fragment outward in the hopes of injuring or killing unprotected enemy troops. Those two functions — anti-armor and anti-personnel — are the dual purposes referenced in the weapon’s name.

The Pentagon built millions of these artillery shells from the 1970s to the 1990s, according to government records, and fired 25,000 of them during the Persian Gulf war. Combined with the 17,200 ground-launched rockets carrying the same type of submunitions that the Army and Marine Corps fired, the United States launched more than 13.7 million of the grenades at Iraqi targets in the 1991 conflict.

Army and Marine Corps artillery shells of this type are tested in Yuma, Ariz., in a relatively flat area of hard-packed soil that is free of vegetation, the ideal setting for the grenades to explode on impact.

But in a conflict, these shells are fired in a wide variety of places that force dud rates up to 10 percent, and in some cases even higher, especially when they land in water, sand, mud or soft ground like plowed fields. The fuzes on the grenades released by the M864 are designed to explode when they hit hard targets like armored vehicles and bunkers, Mr. Vosburgh said.

“Those fuzes rely on impact and if you land in something soft, you may not get the shock you need,” Mr. Vosburgh said. The lightweight grenades often become snagged in tree branches or bushes and fail to explode as well.

A senior defense official on Friday evening confirmed that M864 shells would be sent to Ukraine and acknowledged that environmental factors can affect their performance, but said the Defense Department did not believe that terrain issues would result in a substantially higher dud rate.

The United States military designed many of its modern models of cluster weapons in the 1970s and 1980s with a principal mission in mind: stopping a Soviet invasion of Western Europe by dropping tens of millions of submunitions on tanks and armored vehicles in what was then East Germany during preparations for an attack.