A country cannot simultaneously prepare and prevent war.

One cannot simultaneously prevent and prepare for war

So long as there are men there will be wars. So long as there are men there will be wars.

So long as there are men there will be wars

When asked how World War III would be fought, Einstein replied that he didn't know. But he knew how World War IV would be fought: With sticks and stones!

I do not know how the third world war will be fought, but I can tell you what they will use in the fourth... rocks."