from long ago...

An interstellar war had developed between humans and another race. On the premise that neither side would benefit from all-out warfare, it was proposed that two teams of scientists, one human and one alien, would be sequestered separately and the first race to come up with a working time machine would be declared the winners of the whole shooting match. The human scientists heard that the aliens had succeeded in developing a working prototype, and so they redoubled their efforts and came up with their own version that actually worked. It turned out that the alien's machine was fake and that they had leaked information about their success in order to psych out the competition... but it had simply spurred the humans on to make the real thing.

I always liked that concept.