Critics of the Bush administration who have urged active peace diplomacy are hard-pressed to gainsay its seeming turnaround after years of neglect. Secretary of State Condoleezza Rice has convincingly projected seriousness, and many want to support her new activism. Even if the prospects for peace seem small, most breakthroughs in history come unexpectedly, often through surprising acts of leadership.

But even aside from the obvious obstacles (divided Palestinians, weak Israeli leadership, other American priorities), it is hard to separate the prospects for peace from the way we arrived at this point – or from other regional issues that will inevitably be affected. The fact is, without quick improvements in Palestinians’ lives and a new U.S. approach to the problem of Hamas, any success achieved at the summit would be short-lived.

The U.S. proposal for peace talks arrived immediately after the Hamas takeover of Gaza, which was entirely unanticipated by a policy intended to isolate Hamas and allow Fatah to defeat it. This took place, of course, after the unexpected election of Hamas, which highlighted contradictions in American policy. For many observers, it is not easy to place faith in new diplomatic moves that were in large part intended to deal with the previous policy failure.

It is also difficult to forget the other Middle East issue looming in the background – one that trumps the Palestinian-Israeli conflict as a national security priority for both Israel and the Bush administration. Any optimism about the Arab-Israeli negotiations may sideline the effort to question possible plans for war with Iran. The summit is partly intended to build an anti-Iran coalition, but is it a coalition for containment or for war? (It is probably the former, but one is uncomfortable making a bet.)

One cannot resist seeing an opportunity for diplomatic success, but regardless of the type of document that emerges out of Annapolis, two factors could doom Palestinian-Israeli peacemaking.

The first is what happens in the West Bank the morning after. Neither Israelis nor Palestinians have faith in summits and declarations. If there is no profound transformation on the ground, such as the removal of a significant number of roadblocks and checkpoints (the single most detrimental factor for the Palestinian economy and psychology), Annapolis will become a new metaphor for diplomatic failure.

It is important that Arab governments participate, but it is also important to remember why. The problem for American diplomacy is not winning Israeli public opinion. The aim is to bolster Palestinian Authority President Mahmoud Abbas’ government and to retain cooperation with Arab governments facing an angry Arab public. The pressing need is for significant gains for the Palestinians. The aim of Arab participation is to help Prime Minister Ehud Olmert domestically (through normalization with states such as Saudi Arabia) to offer tangible Israeli concessions. Without these, progress is impossible.

The second factor is Hamas, which not only controls Gaza but has significant assets in the West Bank. Hamas’ central case – that diplomacy does not pay – may be made for it at the summit. But assuming the parties succeed in offering tangible benefits, Hamas will still be a factor. It retains the capacity to revive large-scale violence, which would inevitably alter priorities and make diplomacy more difficult. And if the aim of diplomacy is to isolate and ultimately defeat Hamas, its incentive to act early will be great. One reason it moved forcefully in Gaza was the perception that Americans, Arabs and Mr. Abbas were helping Fatah militarily and economically to enable it to overtake Hamas. Why would Hamas wait?

This suggests that any prospect of success at Annapolis requires a new strategy toward Hamas. As soon as the summit ends, a signal must be sent to Hamas that it could gain if it at least acquiesced. This entails offering it economic relief in Gaza, not additional hardship. It entails encouraging Arab allies, especially Saudi Arabia and Egypt, to engage it and try to prepare conditions for a revival of negotiations with Fatah. Hamas will, of course, have to accept that there can be only one Palestinian Authority, but there are signs of divisions within Hamas on this issue already.

Without such a new strategy, it is difficult to imagine how even modest progress could be attained in the weeks after the Annapolis meeting.

Shibley Telhami is Anwar Sadat professor of peace and development at the University of Maryland and senior fellow at the Saban Center of the Brookings Institution. His e-mail is sadat@gvpt.umd.edu.