The Chetniks, a Yugoslav Royalist and Serbian nationalist movement and guerrilla force, committed numerous war crimes during the Second World War, primarily directed against the non-Serb population of the Kingdom of Yugoslavia, mainly Muslims and Croats, and against Communist-led Yugoslav Partisans and their supporters. Most historians who have considered the question regard the Chetnik crimes against Muslims and Croats during this period as constituting genocide. The Chetnik movement drew its members from the interwar Chetnik Association and various Serb nationalist groups. Some Chetnik ideologues were inspired by the Stevan Moljević's Homogeneous Serbia memorandum in July 1941, that defined the borders of an ethnically pure Greater Serbia. A similar document was put forward to the Yugoslav government-in-exile in September 1941. The Yugoslav government embraced the Chetniks and their basic ideas, which were already a part of the political framework of pre-war Yugoslavia. A December 1941 directive, attributed to Chetnik leader Draža Mihailović, explicitly ordered the ethnic cleansing of Muslims and Croats from Sandžak and Bosnia and Herzegovina. One of the chief Chetnik ideologues, Dragiša Vasić, argued in May 1942 that population transfers and deportations should be carried out in the postwar period. From the start of the war, the Chetniks expelled Muslims and Croats from areas they controlled, and engaged in mass killings. In late 1941, they connected with various independent pro-Chetnik groups that participated in revolts against the Ustaše-led Independent State of Croatia (NDH). With fascist Italy's help, the Chetniks established a form of civil and military government in large parts of eastern Bosnia, which was followed by discriminatory measures and systematic massacres of non-Serbs in the region. The Chetnik genocidal campaign reached a peak between October 1942 and February 1943. Military defeats and the loss of Allied support compelled the Chetniks to moderate their policy towards Croats and Muslims. Despite these efforts, massacres of civilians continued until the end of the war. The terror tactics against the Croats were, to at least an extent, a reaction to the terror carried out by the Ustaše; however, the largest Chetnik massacres took place in eastern Bosnia where they preceded any significant Ustaše operations. Croats and Bosniaks living in areas intended to be part of Greater Serbia were to be cleansed of non-Serbs regardless, in accordance with Mihailović's directive of 20 December 1941. Estimates of the number of deaths caused by the Chetniks in Croatia and Bosnia and Herzegovina range from 50,000