The stalemate in negotiations with the Palestinians and the assumption that it's impossible at present to reach a final-status solution have revived the idea of evacuating part of the West Bank unilaterally. Supporters of this idea believe that current trends, especially the expansion of the settlement enterprise, must be stopped before taking a decision that will anchor the two-state solution. A unilateral evacuation, they believe, will create a two-state reality that will make it easier to implement a final-status agreement.

But Israel's experience with unilateral moves proves the opposite. Evacuations and withdrawals that were not part of an agreement were exploited by hard-liners on both sides to make it difficult to reach a permanent arrangement.

The building of a separation barrier under the slogan "We are here and they are there" quickly shifted settlement construction to the "Palestinian" side of that barrier. If for decades most of the construction was concentrated inside settlement blocs, in the past few years more housing units have been set up in isolated settlements, and the number of Israelis living there has reached some 100,000.

No less important is the fact that Israelis believe that the barrier's route will turn into the border. They believe this even though this route annexes 8 percent of the West Bank, which Israel will not be able to return in a land swap. Moreover, the barrier's route is around 900 kilometers long - three times the length of the Green Line - and penetrates into the Palestinian state more than 20 kilometers east of the Green Line.

Speeding up the settlement enterprise on land west of the fence will strengthen the Israeli public's position and make it complicated for Israel to agree on a compromise border with the Palestinians, who have proposed that 2 percent of the West Bank be involved in a land swap.

The same was the case with the Gaza withdrawal. The attempt to bolster the settlement enterprise in return for the disengagement - as then-Prime Minister Ariel Sharon declared - was perceived as a military victory for Hamas at the expense of Fatah. It was one of the key reasons for Hamas' success in the 2006 Palestinian elections.

Hamas' military takeover of Gaza a year later effectively took the Strip away from the Palestinian Authority - the Palestinians who would achieve a final-status agreement with Israel. That development served the opponents of an agreement on the Israeli side. They said there was no single Palestinian partner for an agreement, and that Hamas would take over the West Bank after an agreement. The proponents of unilateralism completely ignore the ideology of the current government, which is not interested in a final-status solution, and want a say about the scope of the solution. But that's an illusion. The past two decades have taught us that it's impossible to leap over an abyss by jumping twice.

When evacuating the settlements that lie beyond the fence, where a few generations of the Gush Emunim movement live, Israel will have to foot the bill for a permanent arrangement. A unilateral withdrawal is likely to succeed if it's a full withdrawal at a time when the conflict is purely territorial, as happened when the French withdrew from Algeria and evacuated the French citizens living there. This isn't the case with Israel since here issues such as diplomatic recognition and the refugees' right of return are involved.

So in the long term, unilateral moves may actually postpone achieving the strategic goal - an agreed-on separation from the Palestinians - which would grant Israel the legitimacy to stand up for its rights and interests, even with force.