It’s interesting to think of the Marshall plan not just as humanitarian aid but also as a sort of opening salvo of the cold war against communism. Get western Europe up and running again and a part of the global capitalist economy and have the resulting prosperity be it’s own propaganda. In even more immediate utilitarian terms it’s good economics for the sates because having massive production capabilities isn’t going to do us a lot if other nations can’t afford to buy what we’re selling.