Nobody ever launched an attack without having misgivings beforehand, You ought to have misgivings before; but when the moment of action is come, the hour of misgivings is passed. It is often not possible to go backward from a course which has been adopted in war. A man must answer "Aye" or "No" to the great questions which are put, and by that decision he must be bound.

Churchill speaks: Winston S. Churchill in peace and war : collected speeches, 1897-1963 (ed. Atheneum, 1980)