Defenseless anti-patriotism

George Kateb at Cato Unbound makes a libertarian case against patriotism, concluding:

If no one were a patriot, the world would be better off than it now is, when almost all are patriots. Theorists shouldn’t join in.

Kateb's anti-patriotism is similar to, and effectively amounts to, pacifism, and bears that doctrine's fatal flaw; it doesn't work unless everybody embraces it, which won't happen anytime soon, if ever. Patriotism can be a spur to aggression, and also the only safeguard against aggression. A country with some degree of freedom but no patriotism won't have that freedom very long.