I guess we could just kill everybody who we think might do us harm. But when you are the only person left in America, it will be pretty lonely.
Those nice people who live next door are always so sweet and innocent until they break into your house and kill you and your family. Then your other neighbors get to appear on TV saying “But they were always so quiet and peaceful, I never would have thought”.
Maybe we could just blow them up now, just to be safe.