The twentieth century had dispensed with the formal declaration of war and introduced the fifth column, sabotage, cold war, and war by proxy, but that was only the begining. Summit meetings for disarmament pursued mutual understanding and a balance of power but were also held to learn the strengths and weaknesses of the enemy. The world of the war-or-peace alternative became a world in which war was peace and peace war.
Stanislaw LemWe have no need of other worlds. We need mirrors. We don't know what to do with other worlds. A single world, our own, suffices us; but we can't accept it for what it is.
Stanislaw Lem