I vehemently disagree... Without the Torah there is no need for Jews to live in Israel. The Torah expressly commands the Jews to inhabit the land. But if we did not receive the Torah then we could live anywhere we want. Why should Jews not live on a deserted island in the middle of the pacific ocean? Why not in Uganda as the UN was considering?
Ther Torah is the ONLY reason Jews should be in Israel. And whether the rest of the world believes it or not is not material. All Jews need to be made aware of the importance of the land of Israel to the Jewish people.
This is a big subject and I don't have much time right now. Very roughly, here is a sketch of the argument :
1) Jews should have their own state, to avoid being persecuted again by non-Jews. The Jews deserve an independent state of their own where they can be free and safe more than any other people on earth given all that they have suffered in the exile and all the contributions and achievements that they have brought to humanity.
2) Why in Israel and not in Uganda ?
Because the Jews are a nation and the Land of Israel is their historical homeland (not Uganda). The Jews have maintained a continuous presence in Eretz Israel for thousands of years, even after they were massacred and expelled by the Romans, then by the Muslims.
Because of Judaism (of course !).
3) Why Jews in the land of Israel instead of the Arabs who call themselves "Palestinian" ?
There is no Palestinian people, most of the so-called « Palestinians » are Arabs from surrounding countries who immigrated after the Jews. It was the Jews who turned the desert into a garden and resettled and rebuilt the Land of Israel and made it what it is today. The Arabs have lost whatever claim they may have had to the land by repeatedly refusing to share it and responding to the peace offers of the Jews by wars of aggression and terror.
Obviously, we could elaborate a lot on each point (but I have to go and get some sleep now !). As you can see, I do not ignore judaism - this would be absurd... Still, I don't think the Torah is the only possible foundation for zionism as you claim - although it is my personal belief that it is certainly the deepest and most fundamental foundation of all. At a higher level of understanding and conscience, there is no contradiction between secular and religious zionism : the Torah prescribes the unique history of the Jewish people which, in turn, brings about the rebirth of Eretz Israel and, ultimately, the fulfillment of the prophecies of the Torah.