The thing is, both sides have, as we've established, decent claims (Zionists like myself back the "we were there first+Old Testament promise" idea, the Palestinians say they were there for many years, and had it promised to them in the Declaration (though it gave land to Israel, too.)
What, perhaps, SHULD have happened back in 1917 with the Balfour Declaration would've been giving the Jewish settlers the land that they had overwhelmingly settled and were the vast majority (which would've been most of the east and south of what was then Palestine) as the land for th Jewish State, keep Palestine in the areas where it was left (the north and west) and make Jerusalem a joint and/or nuetral city.
But what's done is done, Israelis have won the land back in war, and, honestly, that's how they and anyone else has really gained and lost the land since the inital settling- by winning and losing it in war.
To DingleberryJones:
Zionism is the belief in a Jewish State and Jewish sovereignty in the land that they believe is theirs (which is, give or take some parts of it, what is now Israel.)
So yes, Israelis, and really any Jew who beleives and supports a Jewish State for the glory of the religion (which sounds a bit tired in this age, but as Christians and Muslims have used it before, I suppose why not Jews too) and for protection (which IS needed, as 2,000 years of pogroms have proven; in any case, in my opinion, I believe all races and religions should have at least one "homes state," like Israel for the Jews, Europe and much of the West for Christians, Mecca and the Arabic-Persian States for Persians, and on.)