Israeli Defense Minister Ehud Barak recently warned that if negotiations with the Palestinians do not yield results soon, Israel might consider “unilateral measures” in the occupied West Bank. He didn’t specify what those might be, but several others have suggested that Israel create “temporary” or “provisional” unilaterally-imposed new borders in the territory. This idea is simple, superficially appealing and profoundly dangerous.

Secretary of State Hillary Rodham Clinton is correct in warning that unilateralism runs counter to the whole framework of a negotiated agreement. Rather than calming the situation on the ground, this could greatly inflame an already tense situation. Whatever the professed or real intentions behind such a move, Palestinians and other Arabs will assume that what is enacted as “temporary” will be at least semi-permanent (if not, indeed, permanent). They will believe that Israel is imposing unilaterally, by force and fiat, what it could not get Palestinians to accept at the negotiating table.

Many intelligent and informed observers appear to labor under the illusion that because Palestinians and Israelis have made significant progress at certain stages of negotiations on borders (not including Jerusalem), there is a general consensus on “what the final borders will look like.”

This is incorrect on two major counts.

First, there is no agreement on the percentage of West Bank territory to be included in a land swap. During the last major negotiations on the issue, former prime minister Ehud Olmert reportedly suggested Israel retain something like 6.9% of the area with Palestinian President Mahmoud Abbas proposing 1.9%.

Secondly, many of the areas the sides cannot agree upon are strategically located. For example, the Israeli settlement of Efrata, an outlying area of the “Etzion Bloc,” cuts directly across Route 60, a crucial West Bank North-South artery. Anything the present Israeli government imposes unilaterally on questions like these will be understood by Palestinians not as constructive or helpful, but instead as a unilateral land grab that prejudices one of the most important final status issues: borders.

There are unilateral steps both sides could take that are constructive, just not those that seem to prejudice the outcome of key issues.

The Palestinian institution-building program, for instance, led by Prime Minister Salam Fayyad does not seek Israeli permission but does involve cooperation with Israeli security forces to reduce violence and ensure law and order. That’s constructive unilateralism. Any Israeli unilateral moves to dismantle “unauthorized” settlement outposts, curb settler violence, halt or slow settlement expansion, increase access and mobility for Palestinians, or similar measures would also be constructive. Such moves would ease tensions on the ground and enhance the prospects for resuming negotiations. Anything that brings us closer to a two-state solution is welcome.

But such a solution must be negotiated, not imposed. When Israel has negotiated agreements with Egypt, Jordan and, indeed, the Palestinians, both sides have had a clear interest in making them work. When Israel has acted unilaterally, such as in Gaza or southern Lebanon, no one on the other side has had a vested interest in ensuring a constructive outcome, with predictable consequences.

The lessons of this history are clear. Unilateral Israeli territorial actions in the West Bank are unlikely to promote peace; rather, they would almost certainly undermine both realities on the ground and the prospects for a real, negotiated agreement.