[6][7] As early as May 1968, the BNA's Main Political Directorate launched a propaganda campaign to explain to the army the events in Czechoslovakia.

Immediate military training began in early July, and by the end of the same month it was being carried out in Bulgaria under the control of Soviet officers.

On 20 August 1968, the regiments received a combat order signed by the Minister of People's Defence Dobri Dzhurov and the Chief of the General Staff Atanas Semerdzhiev.

That day, at 06:00, the 22nd Motorized Rifle Regiment (as part of the Soviet 7th Guards Airborne Division) was ordered to enter Czechoslovakia and capture the airports at Prague and Vodochody.

On September 13, the Czechoslovak Defence Minister Martin Dzúr issued an oral note demanding that the Bulgarian military presence be withdrawn.

[11] The defence policy of the country was managed by the Ministry of People's Defense (Министерство на Народната Отбрана (МНО), headed by a professional officer such as a General of the Army or a Colonel General), under the direct supervision of the Bulgarian Communist Party, whose leader was overall commander in chief of the People's Army.

Some of this equipment were 500 combat aircraft, 3,000 (mostly T-55) tanks, 2,000 armored vehicles, 2,500 artillery systems, 33 navy vessels, 67 Scud missiles, and 24 SS-23 rocket launchers.