Pentagon Balks at Sending Ukraine Long-Range Bombs

It’s not fear of escalation. It’s fear of being too late.

By , a Pentagon and national security reporter at Foreign Policy.
Two GBU-39 Small Diameter Bombs sit in the munitions storage area at Al Udeid Air Base in Qatar on Nov. 27, 2020.
Two GBU-39 Small Diameter Bombs sit in the munitions storage area at Al Udeid Air Base in Qatar on Nov. 27, 2020.
Two GBU-39 Small Diameter Bombs sit in the munitions storage area at Al Udeid Air Base in Qatar on Nov. 27, 2020. U.S. Air National Guard photo by Staff Sgt. Jordan Martin

U.S. Defense Department officials are raising concerns about a proposal to send Ukraine small precision-guided bombs that would allow Kyiv to strike Russian targets nearly 100 miles away, according to sources familiar with the debate, fearing that the timeline for deploying the weapons could take far too long.

Under a plan proposed by the U.S. weapons manufacturer Boeing and first reported by Reuters in November, the United States could provide the so-called Ground-Launched Small Diameter Bomb (GLSDB) to Ukraine. The transfer, if completed, would give Ukraine weapons with twice the range of the precision munitions the United States has already supplied for HIMARS batteries and would enable Ukraine to hit targets that have been out of reach for the duration of the war.

Ukraine has repeatedly pledged not to fire U.S.- and NATO-provided weapons onto Russian soil in a move that American officials worry could escalate the war, a designation that does not apply to Ukrainian territories occupied by Russia, such as Crimea. But the Biden administration has balked at sending the U.S.-made Army Tactical Missile System, known as ATACMS—precision rounds that would give Ukraine the capability to hit Russian targets nearly 200 miles from the front lines—despite lobbying from some NATO allies.

U.S. Defense Department officials are raising concerns about a proposal to send Ukraine small precision-guided bombs that would allow Kyiv to strike Russian targets nearly 100 miles away, according to sources familiar with the debate, fearing that the timeline for deploying the weapons could take far too long.

Under a plan proposed by the U.S. weapons manufacturer Boeing and first reported by Reuters in November, the United States could provide the so-called Ground-Launched Small Diameter Bomb (GLSDB) to Ukraine. The transfer, if completed, would give Ukraine weapons with twice the range of the precision munitions the United States has already supplied for HIMARS batteries and would enable Ukraine to hit targets that have been out of reach for the duration of the war.

Ukraine has repeatedly pledged not to fire U.S.- and NATO-provided weapons onto Russian soil in a move that American officials worry could escalate the war, a designation that does not apply to Ukrainian territories occupied by Russia, such as Crimea. But the Biden administration has balked at sending the U.S.-made Army Tactical Missile System, known as ATACMS—precision rounds that would give Ukraine the capability to hit Russian targets nearly 200 miles from the front lines—despite lobbying from some NATO allies.

But the small diameter bomb, known as the SDB in Pentagon parlance, has not been subjected to the administration-wide debate over U.S. weapons provisions to Ukraine potentially provoking Russian escalation, a fear that previously snagged U.S.-made arms including the Javelin anti-tank system, 155 mm howitzer guns, and HIMARS batteries before they were subsequently approved for transfer to Ukraine. The Wall Street Journal previously reported that the United States had even modified HIMARS batteries sent to Ukraine to prevent them from firing the long-range ATACMS missiles. 

Instead, officials inside the Office of the Secretary of Defense and the U.S. Air Force are concerned that the long lead time to deploy the SDB could render the weapons redundant given the fast pace of fighting in Ukraine, which has not let up in the Donbas region in towns such as Bakhmut and Soledar despite the onset of a punishing winter. 

The ground-launched variant of the SDB, which is jointly produced by Boeing and the Swedish manufacturer Saab, uses a rocket motor to help launch it to altitude before gliding to its target, giving it the ability to fly around terrain or circle back to a target. GBU-39 SDBs would need to be paired with M26 rocket motors—the two main components of the GLSDB—before being used in combat, a process that would take months. But proponents of the move are worried that the dithering could slow down that process even more, pushing the timeline back for when Ukraine fields the weapon as industry waits for the Pentagon’s signoff. 

“There’s like a chicken and egg problem,” said one congressional aide familiar with the debate. “It’s bureaucratic fucktardery that’s messing with it now, not political dynamics.”

Estimates vary on how long the integration could take: John Hardie and Bradley Bowman, both analysts at the hawkish Foundation for Defense of Democracies (FDD) in Washington, estimated that Ukraine could get two launchers and 24 weapons within nine months after the Pentagon approves the plan, and 12 launchers and 750 bombs by the end of 2024, without having to build new weapons but simply by integrating old ones already in U.S. stocks. But despite the long lead time, advocates argue that Russia’s invasion is likely to stretch on for months, meaning the system will still be useful when it arrives. 

“Every day the Pentagon delays a decision is a day we push back when Kyiv would actually have this capability in their hands,” Bowman told Foreign Policy. The GLSDB is paired with its own launcher that resembles a cargo container but is distinct from the HIMARS or European-provided multiple launch rocket systems. 

Lt. Col. Garron Garn, a Pentagon spokesperson, declined to provide details on internal talks about military aid to Ukraine but said the agency was in “regular contact” with Kyiv to assess the Ukrainians’ weapons requirements. “As evidenced by their determination on the battlefield, they continue to employ the capabilities provided to them by the U.S. and international community to great effect in defense of their sovereign country,” he said.

Boeing declined to comment on the plan. But Ukrainian officials remain hopeful that any internal impediments to the deal can be solved quickly. 

“We’re just trying to understand how to provide the necessary improvement of these bombs,” one Ukrainian military official told Foreign Policy, speaking on condition of anonymity to speak about the planned transfer. “Hopefully in the next package we will receive it.”

The 250-pound precision bomb—about 50 pounds heavier than the Guided Multiple Launch Rocket System (GMLRS) munitions that the United States has already provided—could prove effective in rooting out reinforced Russian positions, such as trenches, and can be launched from hidden positions to avoid being spotted. But it is still smaller than the ATACMS munition, which is about two times heavier.

“If you get something that is precision-guided and brings a heavier munition, it’s going to be useful,” said Rob Lee, a senior fellow in the Foreign Policy Research Institute’s Eurasia Program. “And bombs, if you’re dealing with defensive positions and trenches, GMLRS and other munitions are not as effective because they’re not as large a warhead.” The weapon was successfully tested by Boeing and Saab in 2019, but it hasn’t been purchased by any foreign military as of 2023. 

The debate comes as Ukraine is beginning to show improved range on the battlefield even without receiving the highest-grade NATO-standard long-range weapons. Ukraine’s top arms conglomerate, Ukroboronprom, recently tested kamikaze drones that have a range of more than 600 miles, and the Russian defense ministry has claimed that Ukraine is already using long-range unmanned aerial vehicles to launch attacks on air bases, though the cause of recent strikes remains unclear. That has sparked debate over whether Western countries should be sending longer-range weapons of their own, such as ATACMS, which may be more accurate.

“Putin is betting on more delays. He must lose that bet,” Lithuanian Foreign Minister Gabrielius Landsbergis tweeted on Wednesday. “Ukraine has more than earned our support and respect. It’s time to send ATACMS and unleash the Leopards,” he added, referring to the long-sought-after German tanks that have not yet been sent to Ukraine (though Poland has indicated it plans to donate Leopard tanks to Ukraine). A deadly HIMARS strike against a Russian barracks in the occupied city of Makiivka at the start of the new year was the latest sign of Ukraine’s effectiveness using long-range weapons. 

Even as the United States has redoubled efforts to provide aid to Ukraine, including $3 billion in military aid this month that will include 50 Bradley Fighting Vehicles, Ukrainian officials are concerned that they don’t have enough long-range firepower to go on the offensive and continue liberating Russian-occupied territories. And Russia may be readying an effort to fight back beyond the current toe-to-toe fighting in the Donbas region: Iran is said to be preparing to send Russia new short-range ballistic missiles to relieve the Kremlin’s depleted arsenal. 

“There are Russian targets in Ukraine that are difficult to reach with what we’ve provided to this point,” said Bowman, the FDD analyst. “Foremost among them is Crimea. We need to make sure that Ukraine has the means to effectively target Russian occupying forces in Crimea.” 

But even as Ukraine lobbies for more state-of-the-art long-range bombs and munitions, after constant Russian targeting of the Donbas cities of Bakhmut and Soledar, the Ukrainians will also need to focus on the rate of newly trained troops arriving for battle and artillery ammo coming from the West, experts said. 

“A lot of it comes back to, do they have enough artillery ammunition, and also, do they have enough well-trained units that can do offensive operations?” Lee said. “And those are still open questions.”

Jack Detsch is a Pentagon and national security reporter at Foreign Policy. Twitter: @JackDetsch

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