Well, it's such a relief to see that I was wrong, and that the OP question didn't actually engender vigorous debate and vituperation....
Look, there's Zionism and there's religious Zionism, and the two are not necessarily the same thing. And there's more than one kind of each.
The classic Zionism is not religious. It was a political movement that espoused the idea that the Jewish People needed a homeland if they were to survive and thrive in the modern world. And that homeland should be the last place that Jews had a political state of their own: the Land of Israel. After all, there have been Jewish communities in Israel continuously since the earliest days, even when the majority of the Jewish People have been living in exile: we never gave up our claim to the land, we only lacked the power to make it real.
Originally, as Caladan pointed out, Zionists who were petitioning first the Ottoman Empire and then the British Empire to create a Jewish State in what was then referred to as Palestine (the name having been given to the place by the Romans as Syria Palestinia, replacing the older Judaea, as a punishment after the failed Jewish Revolt of 135 CE) did not ask for the entirety of Palestine, but for a portion of it, the rest to be shared with the Arabs who lived there. It was Arab refusal to share the land that ended up causing war.
Religious Zionism does hold that the land belongs to the Jews because it was promised by God, in verses such as those Flankerl helpfully cited. But even some religious Zionists (myself included) are willing to give up some of the land if it would buy peace.
So far there simply hasn't been any trustworthy partnership for peace, though. In 1999, Arafat was offered a deal that would've given the Palestinians 97.5% of the land they asked for, with the remaining 2.5% being subject to a land swap; he was offered full autonomy, support, and financial remuneration for Palestinian claims of losses. He turned it down and began the Second Intifada. Rather than work with those who claim to be Arafat's inheritors, even, the Palestinians turned to a terrorist organization and elected their members into office. Who would Israel actually deal with? The terrorists? The leaders who refused the best offer they were ever going to get in favor of more violence?
If a real partner for peace emerges on the Palestinian side, there will be peace. In the meantime, no one wins. Israel takes hits, tries to keep the terrorists at bay, and gets called Nazis and genocides by the rest of the world. Which is ridiculous: Israel is the best-armed, best-trained military power in that part of the world. If they were actually going to commit genocide, there wouldn't be any Palestinians left to complain about it. Israel's security would be far better assured if they just steamrolled over everyone in a massive assault. But they don't do that: they play this long, drawn-out game of waiting, trying to keep the casualty tally down, trying not to incur collateral damage if possible, trying to keep the area safe for the day when the Palestinians might change their minds and get some sense back. That's not the genocidal move, that's the empathic and compassionate move. But of course, nobody wants to see that, because it spoils the black-and-white, simplistic paradigm of the powerful bad guy and the oppressed underdog who has right on his side.
All of which is not to say that Israel hasn't made some mistakes, or that it doesn't have a lot of work to do fixing civil rights issues for its citizens. It has, and it does. But that's not the same thing as saying that they're tyrants or oppressors. It just means that, like every other country on earth, it's a political entity run by human beings, who are flawed.
Israel is the Jewish State. It should remain the Jewish State, with Jerusalem as its capital. But it should have tolerance for all its citizens, whether Jewish, Muslim, or Christian, and there should be no civil rights problems for Israeli Arabs. And if the chance for peace with the Palestinians ever really presents itself, Israel should take it, as long as the price is not the end of the State of Israel. And that means a two-state solution, because the so-called "one-state solution" is just another way of ensuring that the Jewish State is wiped off the map.
