They believed containment, the strategy to stop the expansion of an enemy, would stop the spread of communism.
Ohh I know this it either A or B and I think it B
Upon the outbreak hostilities in September 1939, FDR re-asserted American neutrality, noting, however, that he could not "ask that every American remain neutral in thought as well." He did his best, then, to nudge the United States towards supporting Great Britain, supplying that nation with all aid "short of war."