If your Soviet neighbor is trying to set fire to your house, you can't be worrying about the Arab down the block. If suddenly it's the Arab in your backyard , you can't be worrying about the People's Republic of China and if one day the ChiComs show up at your front door with an eviction notice in one hand and a Molotov cocktail in the other, then the last thing you're going do is look over his shoulder for a walking corpse.
Max Brooks (2006). “World War Z: An Oral History of the Zombie War”, p.47, Broadway Books