These assumptions, when combined, cause states to behave in particular ways. Specifically, in a world where there is some chance—even just a small one—that other states might have malign intentions as well as formidable offensive military capabilities, states tend to fear each other. That fear is compounded by what I call the “9-1-1” problem—the fact that there is no night watchman in an anarchic system whom states can call if trouble comes knocking at their door. Accordingly, they recognize they must look out for their own survival, and the best way to do that is to be especially powerful.