To carry on a war for the overthrow of the international bourgeoisie, a war which is a hundred times more difficult, protracted and complex than the most stubborn of ordinary wars between states, and to renounce in advance any change of tack, or any utilisation of a conflict of interests (even if temporary) among one's enemies, or any conciliation or compromise with possible allies (even if they are temporary, unstable, vacillating or conditional allies) — is that not ridiculous in the extreme?

Left-Wing Communism, An Infantile Disorder (April - May 1920).