The Chetniks, formally the Chetnik Detachments of the Yugoslav Army, and also the Yugoslav Army in the Homeland and informally colloquially the Ravna Gora Movement, was a Yugoslav royalist and Serbian nationalist movement and guerrilla force in Axis-occupied Yugoslavia. Although it was not a homogeneous movement, it was led by Draža Mihailović. While it was anti-Axis in its long-term goals and engaged in marginal resistance activities for limited periods, it also engaged in tactical or selective collaboration with Axis forces for almost all of the war. The Chetnik movement adopted a policy of collaboration with regard to the Axis, and engaged in cooperation to one degree or another by both establishing a modus vivendi and operating as "legalised" auxiliary forces under Axis control. Over a period of time, and in different parts of the country, the movement was progressively drawn into collaboration agreements: first with the puppet Government of National Salvation in the German-occupied territory of Serbia, then with the Italians in occupied Dalmatia and Montenegro, with some of the Ustaše forces in northern Bosnia, and, after the Italian capitulation in September 1943, with the Germans directly.
The Chetniks were active in the uprising in the German-occupied territory of Serbia from July to December 1941. Following the initial success of the uprising, the German occupiers enacted Adolf Hitler's formula for suppressing anti-Nazi resistance in Eastern Europe, a ratio of 100 hostages executed for every German soldier killed and 50 hostages executed for every soldier wounded. In October 1941, German soldiers and Serbian collaborators perpetrated two massacres against civilians in Kraljevo and Kragujevac, with a combined death toll reaching over 4,500 civilians, most of whom were Serbs. This convinced Mihailović that killing German troops would only result in further unnecessary deaths of tens of thousands of Serbs. As a result, he decided to scale back Chetnik guerrilla attacks and wait for an Allied landing in the Balkans. While Chetnik collaboration reached "extensive and systematic" proportions, the Chetniks themselves referred to their policy of collaboration as "using the enemy". The political scientist Sabrina Ramet has observed, "[b]oth the Chetniks' political program and the extent of their collaboration have been amply, even voluminously, documented; it is more than a bit disappointing, thus, that people can still be found who believe that the Chetniks were doing anything besides attempting to realize a vision of an ethnically homogeneous Greater Serbian state, which they intended to advance, in the short run, by a policy of collaboration with the Axis forces".
