On Wednesday, November 19, 2025, the U.S. Defense Security Cooperation Agency (DSCA) published the Department of State’s approval for the potential sale to Japan of a package of various types of guided air-launched bombs worth up to 82 million USD.
GBU-53/B StormBreaker / Photo: RTX
According to the published notice, the government in Tokyo requested the acquisition of 28 GBU-53/B StormBreaker guided bombs (formerly known as the Small Diameter Bomb II, SDB II), which will supplement a previously requested package that includes: 120 GBU-39/B SDB I small-diameter glide bombs, 30 KMU-556 tail guidance kits for conversion into GBU-31 JDAM guided bombs, 20 KMU-559 kits for GBU-32 JDAM bombs, 24 KMU-572 kits for GBU-38 bombs, 24 Mark 82 general-purpose bombs weighing 227 kg, 30 Mark 84 bombs weighing 907 kg, and 21 BLU-110 bombs weighing 454 kg.
In addition, the package also includes the following non-MDE (Major Defense Equipment) items: FMU-139 programmable fuzes, DSU-38 laser seekers for guided bombs, training bombs and bomb components, weapons and associated support equipment, major modifications and maintenance support, training aids, equipment and spare parts, spare and repair parts, consumables, accessories and support for repairs and returns, delivery and support for classified software, classified publications and technical documentation, transportation support, studies and surveys, U.S. government and contractor (Boeing and RTX) engineering, technical, and logistics support services, as well as other related program and logistics support elements.
GBU-53/B StormBreaker
The GBU-53/B StormBreaker is equipped with an innovative tri-mode guidance system that uses infrared imaging and millimeter-wave radar. The weapon can also employ a semi-active laser seeker or GPS and inertial satellite navigation cues transmitted via the Link 16 data link to engage targets accurately. The bomb is capable of striking moving targets in adverse weather conditions, poor visibility, and in the presence of countermeasures.
StormBreaker weighs 93 kg in total (including a 48 kg warhead) and has compact dimensions (176 cm in length and 15–18 cm in diameter). Its engagement range varies from 72 km (moving targets) to 110 km (stationary targets). Thanks to the use of BRU-61/A multiple bomb racks, a single aircraft can carry a significant number of bombs simultaneously. An F-15E can carry 28 bombs, while an F-35 can carry 24 bombs – 8 in its internal weapon bays and 16 on underwing hardpoints.
Previously, this type of bomb has been ordered or is planned to be ordered by the following export users: Australia, Norway, Germany, the Czech Republic, Finland, and Italy.
It is also worth noting that in September of this year, RTX tested a prototype of the ground-launched variant of the small-diameter guided bomb, the GL StormBreaker (Ground Launched).
GBU-39/B SDB I / Image: Boeing
GBU-39/B SDB I
The GBU-39/B SDB I (Small Diameter Bomb) weighs 129 kg (285 pounds), is 1.8 m long (70.8 inches), and has a diameter of 190 mm (7.5 inches). These bombs were first introduced into service, initially with the USAF, in 2005. Owing to their 129 kg weight, they can be carried four at a time on a BRU-61/A multiple ejector rack. As glide bombs, they can strike stationary targets at distances of over 110 km from the release point. Their relatively small 16-kg AFX-757 explosive warhead and accuracy of around 5–8 meters also help limit collateral damage.
Recently, approvals for purchasing this type of bomb have been granted to Norway, Romania, and Morocco, and on September 4 of this year Poland ordered a large batch worth about 120 million USD net. The earlier approval from May 21 covered 1,400 units for up to 180 million USD. Previously, they had been supplied to Japan (under a production contract dated September 30, 2024), Bulgaria, and Ukraine.
They also form part of the GLSDB (Ground-Launched Small Diameter Bomb) precision artillery munition, where they are combined with the rocket motor of the M26 DPICM (Dual-Purpose Improved Conventional Munition) missile. The GLSDB system was showcased in Poland at the latest MSPO defense exhibition in Kielce, in an application for the Chunmoo launcher.