WW1, probably, it would’ve just been a matter of time, and the Germans wouldn’t have spread themselves thin during Kaiserschlacht. Plus the addition of blockades. WW2, the European theatre is iffy, depending on whether or not Hitler overextended himself with operation Barbarossa. The majority of the manpower required to actually push back into Germany was provided by the Americans. Plus, we need to take into account the lend-lease program, and the fact that the island hopping campaign in the pacific was carried out almost entirely by Americans.
(I’m not trying to lord this over anyone, it’s just matter-of-fact.)