Are closed borders/immigration restrictions morally defensible?

[Associate Justice PiT]

I fail to see why it's immoral. A state is nothing more than institution, which seek to monopolise force on a specific territory. Limiting the access of people to that pierce of territory is just the enforcement of the that monopoly. People are welcome to think that the state's monopolising of force on its territory is immoral, but in that case you're not a liberal democrat, but a anarchist.

If we look at human rights which set up the few limitation of the state's monopoly of force. It gives people the right to leave a state's territory, not a right to enter. That right is limited to citizens, who can't be banned from entering their country, unless they have done something to lose their citizenship.

Also this entire discussion sum up why the Left keep losing election and people become more nationalistic. So crabcake if you want to know why UK left EU, a large part of the answer lies in you even asking a question like this.

But why does this right exist? Why is it moral for the northern unemployed man in Britain to "get on his bike" to find work, while it is immoral for an African man to get in his bike to go after work?

Why is it moral to create poverty where it doesn't exist because it exists somewhere else, as opposed ot preserving the former as a wealthy country so that it can work to erase poverty elsewhere?

     That is what gets me about the open borders argument. No country can afford to take in the whole world. If we try, the only result is that everyone here will be poor too. As citizens electing a representative government, there is nothing wrong with choosing to work to preserve our own relative affluence and engaging in foreign aid as we can afford, just as there is nothing wrong with choosing to feed your own family before feeding other families.

[Associate Justice PiT]

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.

     This is actually one of the issues that liberal Democrats face these days. There are many people who believe that excluding other cultures is morally indefensible. However, they also believe strongly in the values of modernity, which are not universally respected across human cultures. This leads to a paradox where they resolve to embrace cultures that reject their most deeply held beliefs. The resolution that is oftentimes adopted is that people simply refuse to criticize or sometimes even acknowledge retrograde views promulgated in other cultures (e.g. Islam endorsing intensely homophobic views).