In Belarus, the military of Belarus is responsible for territorial defense; it is a mixed force of conscripts and professionals that is equipped with Russian or Soviet-era weapons; the Army’s principal combat forces are divided into two geographically based commands, each with two mechanized brigades and an artillery brigade; there are also separate artillery and surface-to-surface missile brigades; the Special Operations Forces has brigades of airborne, air assault, and special forces (spetsnaz) troops, which serve as the military’s high-readiness units; the Air and Air Defense inventory includes about 100 combat aircraft and attack helicopters, as well as air defense brigades and regiments with surface-to-air missiles

Russia is the country’s closest security partner, a relationship that includes an integrated air and missile defense system and joint military training centers and exercises; Russia leases from Belarus a strategic ballistic missile defense site operated by Russian Aerospace Forces and a global communications facility for the Russian Navy; in 2020, the countries signed an agreement allowing for close security cooperation between the Belarusian Ministry of Interior and the Russian National Guard, including protecting public order and key government facilities and combating extremism and terrorism; in 2022, Belarus allowed Russian military forces to stage on its territory for their invasion of Ukraine and continues to supply arms and other aid to the Russian military, including logistical support, medical care, and airfields for Russian combat aircraft; in 2023, Belarus agreed to permit Russia to deploy nuclear weapons on its soil

Belarus has been a member of the Collective Security Treaty Organization (CSTO) since 1994 and has committed an airborne brigade to CSTO's rapid reaction force; the military trains regularly with other CSTO members (2023)