Endsieg [ˈɛndziːk] is German for "final victory". It is used in the meaning that a victory is taken for granted even though all odds are against it.
The word became commonly used in World War I. One of the earliest, if not the first, usage in print was Karl Kraus' satirical story Vor dem Endsieg (Facing Final Victory), published October 1918 in the Austrian magazine Die Fackel (The Torch).
Adolf Hitler used 'Endsieg' in his book Mein Kampf (My Struggle) in 1925 when he asked the rhetorical question if he wanted the final victory over the Jewish people.
In the 30s and 40s, the word was widely used in the propaganda of the 'Third Reich'. 'Endsieg' was part of the Nazi doctrine: Temporary losses (including of civilian lives) notwithstanding, the 'Third Reich' would ultimately prevail, and thus any breakdown in allegiance to Nazi ideology was not to be tolerated. This conjuration of final victory became more desperate in 1943 when allied successes forced Germany onto the defensive. Joseph Goebbels still spoke about the 'Endsieg' as late as March 1945. [1].
The term is today almost exclusively used with reference to its meaning in the Third Reich. Because of this connection with Nazi ideals, it is often banned at German internet forums and other online services, like German eBay [2]. Sometimes 'Endsieg' is also used in a sarcastic way, implying that a goal is unattainable, but that attaining it nevertheless will continue to be expected, no matter what (and that it's not allowed to raise objections due to dictatorship-style leadership).