Are closed borders/immigration restrictions morally defensible?

[Mopsus]

A lot of the justification for borders seem to me like the defence of apartheid gone global. Why is it moral to trap people iin poverty within an artificial creation like a nation-state for the various governments of the world to do as they wish to them

I mean on deontological grounds, closed borders are basically indefensible. People have a right to be free and own themselves (not held within the binds of a government they only have a part of).

So is there really a moral defence that says it is OK for governments to keep someone from migrating from Congo to Europe, but that it is immoral for the Soviet Union to stop Siberians moving to Moscow?

We all have different morals. It is not in my book.

Yes: everything is both defensible and indefensible, because we all have a different moral system. This is one of the key failures of modernity.

It's also relevant to the discussion at hand, because, with unrestricted immigration, a population is guaranteed to host conflicting moral views.

[Mopsus]

OK obviously reading Yankee's responce i didn't make myself clear. I'm not interested in talking about the political ramifications or whatever. I posted it here in this board (and not the Discussion or Economics board) because I want to find a moral perspective using ethical theory on borders. In short, i want to find a way that I can sleep easy at night believing in closed borders on one hand and condemning seemingly governmental intrusions on liberty like apartheid and segregation on the other.

I guess you can take comfort in the fact that the segregation is mutual: the US doesn't like immigration from Mexico, and Mexico doesn't like immigration from Guatemala; South Africa has as much of a right to end immigration from the UK as the UK has to end immigration from South Africa.

[Mopsus]

Okay, here's one: If you believe that closed borders are morally indefensible, that means that you have a moral compass; if you believe that your moral compass points in the right direction, you would want to advance your ethical principles in the world (in fact, you ought to believe that you have a moral obligation to do so); thus, if you thought that the culture of a particular people was immoral, you could justify that people's exclusion from your homeland by appealing to the potentially sinful effect of their presence.