By appointing Tzipi Livni to head the team that will negotiate with the Palestinians at the international peace conference in Annapolis, Prime Minister Ehud Olmert hopes to achieve three goals.

The first of these goals consists of accepting the challenge Livni declared by warning against concessions on national strategic assets and by calling for a measured and cautious approach. Livni allied herself with Defense Minister Ehud Barak, who advocated restricting Olmert's leeway with the Palestinians.

Olmert has come to realize that without support from his defense and foreign ministers, he will have a hard time enlisting public support for an agreement with Palestinian Authority Chairman Mahmoud Abbas. So instead of confronting Livni, he has welcomed her into his team by calling her on Saturday to inform her of his decision.

The offer Olmert is making to Livni is simple enough. Instead of warning against pitfalls, she will now have to lead the troops and avoid them. That way, Livni will be forced to remain committed to a future agreement and share the blame in case the talks fail to produce that agreement.

The premier gains from Livni's appointment in two additional respects. It will help him both with the Palestinians and with the Americans. U.S. Secretary of State Condoleezza Rice, who has so far had to deal with a reluctant Olmert and an eager Livni, will now have to confront her good friend, and say: "Tzipi, your positions are non-starters and they will lead nowhere."

Rice's mission in the region this week is almost impossible. She must bridge the Palestinians' rigid demands and has to defuse their call to draft a detailed agreement before the Annapolis conference. Back in Jerusalem, she has to be mindful of Olmert's threats to disband the coalition if he is pressured into making concessions.

Rice's detractors in Washington say her decision to convene the parties was premature and that she should have first obtained the consent of both parties to make meaningful headway at the conference. Rice will have to work very hard to come back home with the even the inkling of a document of agreement.

In addition, by placing Livni at the head of his time, Olmert has matched the Palestinians' efforts over the past weeks concerning the conference. Prior to the appointment, the Palestinian team had waged a concentrated media effort that focused on the Annapolis talks. The Israeli team, meanwhile, had kept a low profile. Now that team has received a seasoned and high-ranking captain and an experienced diplomat.

And past experience shows that appointing a foreign minister to head peace talks is not an unprecedented move. Shimon Peres handled the final stages of the Oslo Accords as late prime minister Yitzhak Rabin's foreign minister.

The only problem is that Olmert will never allow Livni to succeed and be portrayed as the great peacemaker. This means he and Abbas will have to engage in separate, secret talks. It is within this sort of framework that the big decision will be made.