A truck without a driver has no value in a war. Lend lease was important but the ambition and drive to defeat Germany required huge sacrifices on all sides that are impossible without shared cultural ideals.
Those "shared cultural ideals" amounted to very little beyond "conquer the Nazis, before they conquer us" - as late-war and post-war relations between the USSR and the Western Allies showed. Or, as pre-'39 Western policies showed. The '30's saw the Nazis as an evil...but a useful and "not too" evil, that would (mostly, in effect) protect the West from the greater evil of Soviet Communism.