That's a very critical point, Alouette. There are two issues for the Palestinian arabs: the right to their own state, and the right to live in peace.
The fact is that they never, ever had a state. There never was an arab state of Palestine (or by any other name); it always was under the jurisdiction of someone else. Therefore, Israel's sovereignty is nothing new.
As to the right to live in peace, they have been offered this right repeatedly and have spurned it just as often. Even today, if they said that they wanted to live in peace in Israel and pledged to abandon any efforts to undermine the state of Israel, I have no doubt that the Israeli government would welcome them with open arms.
In my opinion, it is important to recognize that most of these people are officially called "refugees" under international law. Because they are "refugees" it means that they are not living in their permanent homes (how can you be a refugee in your own home?). I'll repeat that: Because they are "refugees" it means that they are not living in their permanent homes (how can you be a refugee in your own home?).
That being the case, I do not believe that Israel will live in peace until the refugees are given a permanent home. I think that it is incument upon arab countries such as Syria, Lebanon, Jordan to open their borders and accept the Palestinian arabs who are refugees. In addition, I believe that they should open their borders to those arabs who currently live west of the Jordan River but would be uncomfortable living under Israeli sovereignty.
Problem solved.