Peng did not oppose Mao's collectivizations in the first phase of the Great Leap, from late 1957– early 1958, but he increasingly opposed it from spring-winter 1958, as the problems which Mao's policies had caused became more evident. In February 1958 Peng gave a speech for the fortieth anniversary of the Soviet Red Army, in which he suggested increased military cooperation between China and the Soviet Union. Mao opposed this suggestion, and began grooming Lin Biao as a viable successor to Peng for the position of Defense Minister. As part of the Great Leap Forward, Mao ordered the formation of a national militia that was controlled by Party members and independent of the PLA, eventually training and arming tens of millions of civilians.