I've seen this quote in various far-right memes. Supposedly, Gen. George S. Patton, upon taking control of Berlin in 1945, said "We defeated the wrong enemy." The Communists, one supposes, were the right enemy. Is it an authentic quotation?
It is at least an accurate paraphrase:
The 1975 Bodyguard of Lies Volume II says:
Patton was relieved of command of the 3rd Army by Eisenhower just after the end of the war for stating publicly that America had been fighting the wrong enemy— Germany instead of Russia
According to the 1987 book Cannon fodder: growing up for Vietnam the exact quote is:
We may have been fighting the wrong enemy (Germany) all along. But while we're here (on the Soviet border), we should go after the bastards now, 'cause we're gonna have to fight 'em eventually.
The 1953 article "We Called Him Uncle Georgie", originally published in The National Guardsman and reprinted in V.F.W. Magazine and Quartermaster Review XXXIII, about Patton by Red Cross worker Betty South, who had direct access to the general at the relavent time, says:
When he went to Berlin to receive the kiss of death from the Russians he remarked shortly, "I think we've been fighting the wrong people all this time, but I've oiled my belly so I can stay with them on the Vodka. My front will be as good as theirs."
Another related exact quote is:
the Germans are the only decent people left in Europe. It's a choice between them and the Russians. I prefer the Germans.