How is the "night watchman state" (or the Rothbardian no-state) going to protect America from Nazism, Communism, Islamism or indeed Canadian red-coats? Oh, that's right. Somehow, free trade is going to save the world and show the Nazi-Commie-Islamist-Canadians that AnCap is the way to go, cuz gold standard or something. And how are you gonna force them to open up their economies to your free trade...? Let's face it, AnCap is a meme ideology only. In the real world, it's simply a front for the same large union-busting corporations as usual.
PS. Fiat currency works.