Some scholars argue that for a long time the collective security doctrine was a sincere and unanimous position of the Soviet leadership, pursuing a purely defensive line,[1][172] whereas others contend that from the very beginning the Soviet Union intended to cooperate with Nazi Germany, collective security being merely tactical counter to some unfriendly German moves.[3][173][174][175] However, perhaps Moscow sought to avoid a great war in Europe because it was not strong enough to fight an offensive war; but there was much disagreement over the policy between Litvinov and Molotov about how to attain that goal, and Stalin alternated between their positions, initially pursuing both contradictory lines simultaneously quite early and abandoning collective security only at some point in 1939.[7][176]