In the closed circle of the war cabinet, pounded by terrible report after terrible report, there had been uncertainty about whether he could fend off the drift to exploring a deal with Hitler. The determination of the larger group trumped the tentativeness of the smaller, and Churchill fulfilled his role as leader by disentangling himself from defeatism--one of his singular achievements at the end of May 1940.
Jon Meacham (2003). “Franklin and Winston: An Intimate Portrait of an Epic Friendship”, p.58, Random House