The peace camp - pathetic naifs that they are - actually believed that the separation fence would prove to be the ultimate weapon against those spoiling for war.

The peace camp believed that pressure brought to bear by the Israeli public, battered by terrorism, would eventually overcome the settlers' ideological opposition to any fence that would split the Land of Israel in two. Peaceniks believed that Ariel Sharon, with his fine-tuned political sensibilities, would succumb to these pressures and agree, despite his own misgivings, to the construction of a fence.

In their minds, members of the peace camp saw the longed-for fence bringing peace closer, or if not peace, at least a unilateral agreement. This was because, according to their naive logic, there were only two reasonable possibilities for the location of the fence, both desirable from their perspective: either along the Green Line, demarcating the future border, or at some line further east, with settlements east of that evacuated.

A third possibility, anchored in a different kind of logic, never occurred to them. It turns out, though, that the fence can also be built east of the Green Line without evacuating a single settlement beyond it.

This kind of fence, now being planned by the government, will not create a separation between Israel and the Palestinians. It will separate between Israelis and Israelis, and between Palestinians and Palestinians. Hopefully, it will block terrorism, but it will also block the creation of a viable and territorially contiguous Palestinian state. Thus, it will prevent the implementation of the two-state solution - the only option that can preserve Israel's character as a Jewish, democratic state.

The fence, upon which so many high hopes have been hung, has been snatched by the settlers and their supporters from the moderates who conceived it, and converted from a tool to bring Israel closer to an accord, to a means of pushing it farther away.

But the naifs have not despaired. They still have another card in hand, and this one, they say, is a winner. What they are referring to is the demographic threat. The figures, after all, speak for themselves. Even the most glazed-eyed dreamers on the right cannot deny them. Within a few years, Palestinian population growth will exceed Israel's, and when that happens, the Palestinians will abruptly stop demanding a state of their own alongside Israel. Instead, they will demand their elementary right - one man, one vote - in a unitary state.

Faced with this scenario, which in practical terms means the end of Zionism, the peace camp applies its commonsensical logic again, and reaches the comforting conclusion that this time the settlers will simply have to give in. After all, the Zionist state is no less precious to them than it is to political moderates. Having no choice, they will be forced to admit the truth of the maxim that if you covet all, you may lose all - and realize at last the need to end the occupation. What the terrorists could not achieve with their bombs and the intifada youth could not achieve with their stones, their parents will achieve in the bedroom.

The trouble is that this hope too could prove to be naive and end up dashed against the rock of religious nationalist fanaticism. The demographic threat, like the public pressure to build a fence, could become a double-edged sword, usurped by the settlers and swung over the heads of those very people who warn against the dangers of continued occupation.

After all, there is nothing like an existential threat to get the whole nation to rally around a cause. In the settlements and parties of the right, the significance of the demographic trend is understood very well. But their conclusion - and there are already discernible signs of it - is likely to be the very opposite of what common sense would dictate. Instead of returning to a smaller but cohesive Israel, the leaders and rabbis of the right may well try to turn the demographic threat itself into an impetus for enlisting all of Israel in a fight to the finish with the Palestinians (the pretext for this all-out war will not be demographic, but defense-related, of course).

While the peace camp hopes that the very real and frightening demographic scenario will convince the settlers to finally sober up - lest the entire Zionist enterprise find itself in mortal danger - the rightists hope that this same demographic threat will convince the whole of Israel to join their ranks.

In the same way that the separation fence, which was supposed to expedite the two-state solution (in our dreams, at least), has become a tool for perpetuating the occupation, the demographic threat, which was presumed to be the winning card of the left, could turn into the doomsday weapon of the right.