The conclusion of the armistice invariably changed the substance of Britain's relations with Bulgaria. Securing the withdrawal of Bulgarian troops from Aegean Greece was seen as a significant diplomatic and tactical success for the British government. As Bulgaria's proximity to the Mediterranean continued to govern Britain's interest in the country, participation in the Bulgarian armistice regime was a valuable new channel for influence on Bulgaria's postwar development. Observations made by British political and military staff in Bulgaria would throw light on the actions and aspirations of local political actors, but also – and even more importantly – on the methods and aims of Soviet foreign policy in Bulgaria, the Balkans and Europe in general. Further, the ACC would be a forum for lower-level great-power cooperation: its functioning would test the desire of the Soviet Union to maintain friendly relations with the Western Allies.

Ironically, the importance of Bulgaria for Britain grew as a result of the Soviet occupation, whereby Bulgaria's military facilities were placed under Soviet control and its government looked to Moscow for internal and international support. Bulgaria's dealings with its neighbours and its attitude to the Western powers would be determined by, and therefore would be symptomatic of, Soviet postwar plans. In the second half of 1944, British leaders were increasingly worried that the Soviet Union might use such a newly acquired position of power in the Balkans to encroach on territories beyond those conceded to it and so endanger long-term British interests further afield.