 After the Tehran Conference, the Partisans received official recognition as the legitimate national liberation force by the Allies, who subsequently set up the Balkan Air Force (under the influence and suggestion of Brigadier Fitzroy Maclean) with the aim to provide increased supplies and tactical air support for the Partisans.In February 1944, Mihailovic's Chetniks failed to fulfill British demands to demolish key bridges over the Morava and Ibar rivers, causing the British to withdraw their liaisons and halt supplying the Chetniks.Although British support for the Chetniks ceased, the Americans were less than enthusiastic about British abandonment of the anti-communist Chetniks.