On paper, the JNA seemed a powerful force, with 2,000 tanks and 300 jet aircraft (mainly Soviet or locally produced). However, by 1991, the majority of this equipment was 30 years old, as the force consisted primarily of T-54/55 tanks and MiG-21 aircraft. Still, the JNA operated around 300 M-84 tanks (a Yugoslav version of the Soviet T-72) and a sizable fleet of ground-attack aircraft, such as the Soko G-4 Super Galeb and the Soko J-22 Orao, whose armament included AGM-65 Maverick guided missiles. By contrast, more modern cheap anti-tank missiles (like the AT-5) and anti-aircraft missiles (like the SA-14) were abundant and were designed to destroy much more advanced weaponry. Before the war the JNA had 169,000 regular troops, including 70,000 professional officers. The fighting in Slovenia brought about a great number of desertions, and the army responded by mobilizing Serbian reserve troops. Approximately 100,000 evaded the draft, and the new conscripts proved an ineffective fighting force. The JNA resorted to reliance on irregular militias. Paramilitary units like the White Eagles, Serbian Guard, Dušan Silni, and Serb Volunteer Guard, which committed a number of massacres against Croat and other non-Serbs civilians, were increasingly used by the Yugoslav and Serb forces. There were also foreign fighters supporting the RSK, mostly from Russia. With the retreat of the JNA forces in 1992, JNA units were reorganized as the Army of Serb Krajina, which was a direct heir to the JNA organization, with little improvement.