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 avoided by many countries, drop small grenades that are built to destroy armored vehicles and troops in the open, but also often fail to explode immediately. Years or even decades later, they can kill adults and children who hit them.
The Pentagon said the weapons they will send to Ukraine have a failure rate of 2.35 percent or less, far better than the usual rate that is common for cluster munitions.
But the Pentagon’s own statements indicate that the cluster munitions in question contain older shells known to have a failure rate of 14 percent or more.
They are 155-millimeter artillery shells that can each fly about 20 miles before breaking up in mid-air and releasing 72 small shells that typically explode on impact along the perimeter of an oval-shaped area larger than a football field.
Pentagon officials said the grenades they will send to Ukraine are an improved version of a type used in Operation Desert Storm in 1991. But the reality is a little more complicated. The shells sent to Kyiv may fly farther than the earlier versions, but they contain the same shells that had miss rates that the Pentagon characterized as unacceptably high.
Al Vosburgh, a retired army colonel trained in bomb disposal, said that once the shooting stops in Ukraine, a massive education campaign is needed to warn civilians about the risks of unexploded ordnance 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 those shells cannot be safely moved by hand.
“You have to put a lot of effort into removing those because you don’t have to move them,” said Mr. Vosburgh, who now runs the non-profit demining group. Golden West. “In an area that’s saturated with them, you’re going to find a lot of bugs, so it’s a slow and methodical process to get rid of them.”
But Biden administration officials said they had little choice but to provide cluster munitions despite their continued danger as Ukraine burns through artillery and tries to make gains in a tense counteroffensive against Russian forces.
Jake Sullivan, the president’s national security adviser, defended the use of the weapons and said Russia had been using them since the start of the war. Ukraine has also used Russian-made cluster munitions, and has repeatedly requested American-made ones, knowing that the United States maintains large stockpiles.
“Ukraine would not use these munitions in any foreign country,” Mr. Sullivan said. “This is their country that they are defending. These are their citizens that they are protecting and they are motivated to use whatever weapons system they have in a way that minimizes risks to those citizens.”
Weapons of this type are prohibited by more than 100 countries, partly because more than half of those killed or injured by them are civilians. Neither the United States nor Russia or Ukraine signed the treaty banning their storage or use.
Analysts say as many as 40 percent of Russia’s cluster munition bombs have resulted in malfunctions.
Brig. Gen. Patrick S. Ryder, a Pentagon spokesman, said the Defense Department conducts extensive testing of the cluster munitions in its stockpiles, and “the ones we are providing to Ukraine are tested at less than a 2.35 percent failure rate.”
Such a rate would mean that for every two shells fired, approximately three unexploded shells would be left scattered on the target area. But the slow rate for these grenades was observed at rates seven times higher in combat.
On Friday, in a briefing to reporters, Colin H. Kahl, the undersecretary of defense for policy, said that the grenades being sent to Ukraine had been tested five times between 1998 and 2020.
“The tests themselves are classified,” he said, adding that he had “high confidence” in their results.
The timing of those tests is consistent with the availability of a shell called M864 whose production ceased in 1996, and an Army official confirmed Friday that the last mass artillery shell live-fire reliability tests the service conducted were on M864 shells at Yuma, Ariz. , in 2020.
The dud rates offered by Pentagon officials vary widely from what bomb disposal technicians and civilian deminers find in the field in post-conflict areas, including the M864 bullet.
US military bomb disposal specialists are trained to exercise extreme caution in areas where cluster munitions have been used, and to expect that about 20 percent of all submunitions, regardless of country of origin, will not explode.
The bullets being sent to Ukraine are often referred to by the name given to those small shells: dual-purpose improved conventional munitions, or DPICM — and pronounced by some officials as dee-PICK-’ems.
The shells, which are about the size and shape of a D-cell battery, are stabilized in flight by a nylon ribbon running from the top. Weighing less than half a pound each, they contain an explosive warhead that will shoot a jet of molten metal down capable of penetrating two and a half inches of armor plate.
The detonation also causes the steel casing of the grenade to fragment outwards in the hope of injuring or killing unprotected enemy troops. Those two functions – anti-armor and anti-personnel – are the dual purposes referenced in the name of the weapon.
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 shells at Iraqi targets in the 1991 conflict.
Army and Marine Corps artillery shells of this type are tested in Yuma, Arizona, in a relatively flat area of hard-packed ground that is free of vegetation, the ideal scenario for the shells to explode on impact.
But in conflict, these shells are fired in a wide variety of places, which force failure rates up to 10 percent, and in some cases even higher, especially when they land in water, sand, mud or soft soil such as plowed fields. The fuses on the grenades released by the M864 are designed to explode when they hit hard targets such as armored vehicles and bunkers, Mr. Vosburgh said.
“Those fuses are impact dependent and if you land in something soft you might not get the shock you need,” Mr Vosburgh said. The light grenades often get stuck in tree branches or bushes and don’t explode either.
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 terrain issues would result in a substantially higher slowness.
The US military designed many of its modern models of cluster munitions in the 1970s and 1980s with a primary mission in mind: to stop a Soviet invasion of Western Europe by dropping tens of millions of submunitions on tanks and armored vehicles in what was then the German Democratic Republic. during preparations for an attack.