What do you call a man you never met? A stranger.
What are you morally forbidden to do to a stranger? You may not murder him. You may not attack him. You may not enslave him. Neither may you rob him.
What are you morally required to do for a stranger? Not much. Even if he seems hungry and asks you for food, you’re probably within your rights to refuse. If you’ve ever been in a large city, you’ve refused to help the homeless on more than one occasion. And even if you think you broke your moral obligation to give, your moral obligation wasn’t strong enough to let the beggar justifiably mug you.
Notice: These common-sense ethics regarding strangers, ethics that almost everyone admits, are unequivocally libertarian. Yes, you have an obligation to leave strangers alone, but charity is optional.
One last question: What fraction of your “fellow citizens” have you actually met? Virtually zero. The vast majority of your countrymen are, in fact, utter strangers to you. When you tell your kid “Don’t take rides from strangers,” you don’t make an exception for anyone who happens to share your citizenship. Modern government – and most of political philosophy – is just a massive effort to pretend otherwise.
The point of the pretense is twofold. First, to make unjustified demands on some strangers’ behalf: You’re going to help the American elderly, the American poor, and the American sick whether you like it or not. Second, to help us forget our basic obligation to leave all strangers alone: We’ve never met you before, but you still owe us.
When libertarians say things like this, people ridicule them as cold and cruel. But they’re just dodging the issue. Even staunch anti-libertarians would be baffled if a homeless man announced, “Give me my money!” instead of asking “Spare change?” After all, the beggar is a stranger. All the libertarian is pointing out is that your other “fellow citizens” are strangers, too. You’re not cold and cruel when you refuse to help; they’re being pushy and totalitarian when they refuse to take no for an answer.
This would be bad enough if modern governments focused on forcing rich strangers to give to poor strangers. But it’s outrageous when the direction of coercion reverses. The most egregious example, of course, is restrictions on immigration. People in the Third World are strangers, but we still have a moral obligation to leave them in peace. Instead, we pass draconian laws forbidding these strangers to work for other complete strangers. And for what? To fulfill our fantastical obligation to maintain the wages of fellow citizens we don’t trust enough to give our kids a ride.