Wiktionary
unwinnable
a. Unable to be won.
Usage examples of "unwinnable".
Like me, he had opposed the Vietnam War, believing that it was misconceived and unwinnable.
General Shoup, who had served in Vietnam and later declared the war unwinnable.
President, this will simply not be taken any other way except as the United States withdrawing from an unwinnable situation in the Balkans," Kercheval said.
It is somewhat more socially liberal than the Centrists but has traditionally considered a war against Haven as unwinnable and believed that the Star Kingdom's interests would be best served by cutting some sort of “deal” with the PRH.