US Prioritizes Ukraine Over Taiwan for Ground-Launched Small Diameter Bomb (GLSDB)

The US government appears to prioritize resolving the urgent conflict in Ukraine over the longer-term threat of tension between China and Taiwan(asia). Recent reports suggest that the sale of the Ground-Launched Small Diameter Bomb (GLSDB) to Taiwan may be delayed for up to three years until Ukraine's needs are met. The GLSDB is a sophisticated weapon that combines the M26 missile with the GBU-39/B SDB guided bomb, allowing for a maximum launch range of 150 km. Developed jointly by Boeing and Swedish defense company SAAB, the GLSDB features an inertial guidance system and GPS, and is set to enter mass production in late 2022 or early 2023.

US officials have repeatedly emphasized the difference between Russia and China, categorizing the former as an immediate "acute strategic threat" and the latter as a "pacing challenge" representing a long-term peer competitor. The Taiwanese Army currently possesses the M142 High Mobility Artillery Rocket System (HIMARS) and the M270 Multiple Launch Rocket System (MLRS), both of which are capable of launching the GLSDB. The addition of the GLSDB would allow Taiwan to create a three-tiered strike capability, along with the Guided Multiple Rocket Launch System (GMRLS) and the Army Tactical Missile System (ATACMS), which have launch ranges of 80 km and 300 km, respectively. The GLSDB can glide towards its target once the rocket motor runs out, significantly increasing its range. The weapon features an advanced anti-jam GPS system-aided inertial navigation system, as well as a programmable electronic fuze and multipurpose, penetrating blast-and-fragmentation warhead. It can engage targets from any angle, including reverse slope engagements.

Although the GLSDB could be used in conjunction with other anti-ship missiles to defend Taiwan's coastline against the Chinese Navy, some experts argue that these systems would only provide a temporary tactical advantage, delaying or complicating China's attack and occupation plans. Ultimately, China's superior air, space, and naval assets would likely prevail. Despite Taiwan's request to purchase the GLSDB, the US has explained that its priority is to supply Ukraine with this type of ammunition, as part of a $2.2 billion aid package. The Ukrainian military could use the GLSDB to strike Russian forces, logistics hubs, strategic terrain in Crimea, and thinly-stretched supply lines in the east. Russia has claimed to have intercepted US-made HIMARS rockets and shot down the GLSDB in Ukraine, demonstrating their advanced military capabilities.

The delay in supplying Taiwan with the GLSDB also highlights the broader issue of post-pandemic supply chain constraints faced by the US defense industry. After depleting their stock of Javelin Anti-Tank Guided Missiles (ATGM), 155-mm artillery rounds, and HIMARS rockets, US defense companies have indicated that it will take several years to increase production and replenish their own stocks. For example, the production of 900,000 155-mm rounds, which Ukraine uses to fire from the M777 howitzers supplied by the US, will only increase from 14,400 to 36,000 per month by 2025. Lockheed Martin, the manufacturer of HIMARS, GMLRS, MLRS, Javelin ATGM, Precision Strike Missile (PrSM), and Terminal High Altitude Air Defense (THAAD), has stated that it will take years to expand its manufacturing capacity at its Arkansas facility, despite increased capital expenditure.