Peter H has left a comment worth more than merely a counter-comment.
Sorry, but the right to a nation-state does not mean denying the right of return (a right guaranteed by international law) so that can preserve its Jewish demographic majority.
Not surprisingly, I disagree - on various levels.
First, the factual one. International law doesn't say what Peter H says it does, and if he's convinced it does, I suggest he show us chapter and verse.
Second, even should he come up with some legal paragraph, that's only the beginning of the story. In any legal system, lawyers exist to find loopholes in laws, judges exist to accept or reject the lawyer's interpretation, and most importantly, lawmakers exist to adapt the laws, which is a nice way of saying to change them.
Third, one of the most serious flaws, and it's very serious, with international law is that it lacks natural mechanisms for the lawyers and judges to do their thing. True, there are international courts and so on, but they and their activities are very thin. A living legal system tinkers with its laws all the time, within the parameters of the constitution. Also, one might add, the lawyers, judges, and lawmakers, and even the constitution, are all subordinate to the sovereign - the electorate. Which brings us to the fourth flaw in international law.
International law has no sovereign. Yes, I know, its adherents would like to regard the Community of States as sovereign, but for that you must postulate that there is a community, and that it operates from some common base. For example, that the governments of all the states are themselves controlled by a sovereign electorate. Or that there is a constitution which the people were directly asked about, and could change if they put their minds to it, according to some legal mechanism that had been written into the constitution itself.
Say you live in a democracy and there's this law which really infuriates you. Since it's a democracy, the way is open for you to mobilize lots of other citizens, and sooner or later, if your cause is plausible and becomes popular enough, you'll succeed in changing the law. This is true on small matters, and large. Say there was a legal situation which required a nation to watch as its nation state was taken from it. In a democracy, the voters could do something about it, as the voters of many European states will tell you; however, if it's international law you're up against, there's no way out.
Which brings us, of course, to the ultimate reason that international law is not relevant to the Right of Return: If indeed it were to be proven that international law requires the Jewish State to cease to exist, then international law would have no right to exist.
PS. The use of pseudo legal terminology and reasoning to deal with political matters, as in this case, shows how weak the entire construct is. Laws are fine things to have, but there are parts of the human condition they can't deal with. They can't cure sicknesses, they can't cure broken hearts, they can't make political issues go away, either, unless it be when the politics are about legal matters.