What are you trying to say? I read
1) It is unethical to treat citizens and immigrants differently. Treating immigrants like citizens strains the resources of ethical country beyond breaking point. Therefore it is ethical to deny immigrants.
2) It is ethical to tell other countries to take care of their people, so they don't come here.
2) Migration is caused by countries "dumping" people on other countries.

On the surface 1) sounds like a principled stance, but it is anything but. First, it is shameful, the argument is selfishness disguised as ethics. We, the people of ethical country, enjoy prosperity. We could not provide this prosperity to all comers without diminishing our own prosperity. Obviously we don't want that. But we neither want to deny a part of the prosperity for some time to migrants because that would not be what ethical people do. So, the ethical answer is to send the migrant back into squalor? Off you go, back to whereever you do not want to be. I think it is obvious this argument is about US, not THEM, and it has a taste of we don't like them no strangers. Sorry, mister, you can't come in from the thunderstorm, there is no cake left for you. Have fun on the trip home over the Mediterranean. Second, it seems to say that any solution must be perfect -- but that's not what I am looking for. Improving the lot of people is a process, not a state. The lot of a migrant is improved if she may live in a country with working institutions and the rule of law, even if they are denied some things naturalized citizens enjoy (like voting. Oh wait, ethical country doesn't seem to mind that though). Now the migrant has a chance to build something for themselves without worrying about drought, war, corruption, oppression, lack of institutions, raider warlords, or religious nutcases, and start on the road of gaining citizenship. I think here at HN we are big on entrepreneurship and personal responsibility, ask the migrant what she would prefer.

Argument 2) is more of an extension of 1). It is ethical to tell others what to do if it improves my lot. You change, so I don't have to. Here we chide other countries that obviously have massive problems already -- otherwise people would not leave in droves -- to get their act together so that we do not have to bother. I mean, telling other countries what to do is par for the course, everybody does this all the time, just think of China. But it doesn't seem to work, I wonder why?

If a country would be organized enough to enact 3) they probably also could create an environment where their people could provide for themselves (granted, maybe they wouldn't, see Russia). The main reason for migration is because individuals cannot provide for themselves in many parts of this planet for various reasons (see above). The migrant takes the largest decision of her life: leaving behind everything she knows, embarking on a long, expensive, and dangerous journey for the fighting chance to make a living somewhere else. It's not the nations that are sending their citizens (and tax base) away, quite to the contrary. It's the citizens that say, I can't provide for myself here. I must seek my fortune elsewhere. Ferrying people back into countries they fled from is not helping the migrant or the originating country.