US nuclear weapons in Belgium

Belgium hosts an estimated 10 to 15 US B61 gravity bombs at Kleine Brogel Air Base under NATO's nuclear sharing arrangements, a role it has filled since the early 1960s. The weapons remain in US custody, guarded by a US munitions support squadron; in wartime, and only after explicit authorization by both the US President and NATO, they would be delivered by Belgian aircraft.

The Belgian Air Component is replacing its F-16s — the assigned dual-capable aircraft for decades — with the F-35A, which reached Kleine Brogel in 2025 and is certified to carry the modernized B61-12. Belgium participates in NATO's Nuclear Planning Group, and successive governments have reaffirmed the hosting role despite recurring parliamentary debate.

As a non-nuclear-weapon state party to the NPT, Belgium does not own or control the weapons; NATO's position is that the arrangement predates the treaty and is compatible with it, a reading contested by supporters of the Treaty on the Prohibition of Nuclear Weapons.

Belgium's first F-35As arrived in country in 2025, and Kleine Brogel's conversion — hardened infrastructure included — follows as deliveries continue; the F-16s hold the nuclear role until the transition completes. The B61-12 rollout across Europe finished in the mid-2020s. Recurring parliamentary pushes toward the prohibition treaty have not shifted government policy.