US long-range bombs headed to Ukraine as ATACMS supply dwindles

By Mike Stone

WASHINGTON (Reuters) - The U.S. is poised to resume shipments to Ukraine of long-range bombs known as Ground-Launched Small Diameter Bombs (GLSDB), after they were upgraded to better counter Russian jamming, two people familiar with the weapon told Reuters.

The munitions will arrive amid reports that Ukraine's supply of similarly-ranged Army Tactical Missile Systems (ATACMS) has been depleted.

The glide-bombs were purchased under the U.S. administration of former President Joe Biden using the Ukraine Security Assistance Initiative. The U.S. has bought nearly $33.2 billion worth of new arms and military equipment for Kyiv directly from U.S. and allied defense contractors.

President Donald Trump's administration agreed on Tuesday to resume military aid and intelligence sharing with Ukraine after Kyiv said it was ready to support Washington's proposal for a 30-day ceasefire with Russia.

In recent weeks, 19 GLSDBs were test-fired to assess the effectiveness of the upgrades. Part of the modifications involved reinforcing connections within the weapon to enhance its resilience, the people said.

The reintroduction of the GLSDB onto the battlefield could occur in the coming days, as a stockpile is already present in Europe. The last time Ukrainians used the weapons was months ago, one of the people said.

Russian jamming had kept many of Ukraine's relatively new long-range GLSDBs from hitting their intended targets, three people familiar with the challenges told Reuters last May.

Ukraine over the last year sought weapons with longer ranges than the 43 miles (69 km) of U.S.-provided GMLRS rockets so Kyiv could attack and disrupt Russian supply lines and muster points.

To answer that call, Boeing offered a new weapon to the Pentagon with a 100-mile (161-km) range, the GLSDB. The glide-bomb has small wings that extend its reach, and it comprises the GBU-39 Small Diameter Bomb (SDB) and the M26 rocket motor, both of which are common in U.S. inventories and relatively inexpensive.

Boeing declined to comment.

But the GLSDB's navigation system, which enables it to be steered around obstacles such as mountains and known anti-air defenses, had been successfully targeted by Russian jamming, the three people briefed on the matter said in May.

The bomb is made jointly by SAAB AB and Boeing, and was in development well before Russia's full-scale invasion of Ukraine in 2022.

Jamming happens when huge amounts of energy are broadcast into an area, overwhelming a device's signal. Russia has used the tactic on Ukrainian radios, drones and even GPS-guidable Excalibur 155-millimeter artillery munitions.

(Reporting by Mike Stone in Washington; Editing by Rod Nickel)