Regarding Yonah`s comment above: I agree that Zionism, the Nation, requires the religious heritage to survive, even just to be complete. However, the reverse dependence may be also true, even as many would be reluctant to admit. Namely, at this historical juncture, as different from previous ones, what future Judaism really has without the existence of Israel?
The two are now inextricably intertwined. Something truly big happened in Jewish history in the return of the nation to a land of its own (which, importantly, it is an intrinsic part of its eschatology – the divinely promised one), and there is no going back to the past anymore, in any clear sense.