For active participation in the sports life of the school, good studies, he got the opportunity to choose a place of service.

On December 25, 1979, the 180th Motorized Rifle Regiment, commanded by Lieutenant Colonel Kasymov,[2][3] ensured the unhindered advance of divisional units by crossing the Amu Darya river at the outset of the Soviet–Afghan War.

In November 1980, by order of the Ministry of Defense, he was appointed chief of staff of the 108th Motor Rifle Division, which was located in the city of Kabul.

In September 1988, he was appointed First Deputy Commander of the 31st Army Corps of the city of Kutaisi (Georgian SSR) in the area of responsibility of the Transcaucasian Military District.

In the spring of 1997, Lieutenant General Kasymov was appointed to the post of Deputy Minister of Defense for Combat Training.