There are plenty of reasons to be cynical about U.S. Secretary of State John Kerry's relaunch of Israeli-Palestinian peace talks. The personalities and the politics involved do not immediately inspire confidence. Nevertheless, I choose not to be negative, partly because it is always easy to sit on the sidelines and take potshots. The more important consideration is, because peace is so essential to the lives and futures of the peoples of the region and to American interests in the Middle East, that any good faith effort deserves support and a chance to succeed. Secretary Kerry has insisted that the talks be held in private with no leaks, hype or "spin". While it makes sense to protect the negotiations from the relentless pressures of the media and other forms of external interference, a cautionary note is in order. There is an intimate relationship between Israeli and Palestinian public opinion and the successful outcome of any peace negotiations. In the end, no matter how clever or skillfully arranged the formula for compromise, it must pass the test of being accepted by both sides. When we have polled both Israeli and Palestinian publics in order to see where compromise can be found, our efforts come up short. Too often what we find is that the most Israelis indicate a willingness to give in any peace agreement falls far short of the Palestinian minimum requirements for a just settlement. The negotiators, if they are worth their salt, know this. They, therefore, address each issue not merely as an abstract problem to be solved, but as a matter which must, in the end, be accepted by their respective publics. Concretizing this imperative, both Israeli and Palestinian leaderships have pledged to submit the product of the negotiations to a referendum. This makes it especially clear that both societies must be ready and willing to endorse any compromise arrangement for peace. Ignoring the vital role that will be played by public opinion in this process, therefore, can doom the entire effort from the start. Peace, like any political compromise, must be grounded in the possible. As I have noted, our polling establishes that, at this point, peace does not appear to be possible. Paralleling the negotiations, the real work that must be done is to expand the range of the possible by changing public attitudes on both sides. This imperative becomes all the more urgent when we see how at any sign of progress the opponents of peace immediately step up their efforts to poison the well of public discourse. Just recall how after the Oslo Accords were signed in 1993, even before the ink had dried, the LIKUD activated their networks in the US and pushed Congress to pass legislation to negatively encumber any Palestinian aid program that might have created Palestinian confidence in the process. Or how after the Wye Agreement was signed in Washington, Ariel Sharon, who opposed the agreement, urged his supporters to "take the hilltops" and establish settlement outposts in sensitive areas of the West Bank. Or how Hamas, in response to each step forward in the peace process, stepped up its campaign of violence in an effort to take the process a step backward by embarrassing the Palestinian leadership and creating fear and mistrust among Israelis. We can be sure that the opponents of peace will be active this time, as well. Even a casual reading of the recent press and political commentary on both sides makes this so very clear. Look, for example, at the hysteria being created in Israel over the government's agreement to free 104 Palestinian long-term prisoners. If left uncontested, the harsh rhetoric created in response to this "confidence building" gesture, may sabotage its implementation or at the very least make it the last such gesture. The question is, will those who support an agreement not only be willing to meet these new challenges, but be able to make up for lost ground due to past failures and decades of hostility and mistrust? So we can agree that the negotiations led by Secretary Kerry must be private, but alongside this effort U.S., Israeli and Palestinian leadership must be bold in changing the public discourse and challenging the opponents of peace. Here is where President Obama can play an especially critical role. His speech in Cairo and his more recent visits and remarks in Jerusalem and Ramallah were important, but these speeches cannot be the end of his involvement. They should be repeated at critical moments during the next few months. Israelis and Palestinians need to be presented a vision of an alternate future, one that is so attractive and compelling that they will be drawn to it. They need to have this future vision so that they can embrace it with hope and contrast it both with the present unacceptable reality and the future that lies before them if they do not change course. At the same time, the President cannot be the only actor in this effort. Those who embrace a different and better future for Israelis and Palestinians need to come together and be strengthened in their resolve to face down those who oppose peace. An initial step the President can take is to convene Jewish and Arab Americans who support peace urging them to work together in support of a just resolution to the Israeli-Palestinian conflict. If the negotiations are to bear fruit and if the product of these efforts is to have any chance for success, it must have a support-base both in the U.S. and in Israel and Palestine. For peace to succeed, there must be a constituency that works for peace. The relaunched peace effort led by Secretary Kerry may or may not succeed. If it does, it will not be because the negotiators, alone, did their work. It will succeed only if both societies are prepared to accept the results of their efforts. If they fail to reach an agreement, or if they conclude one, but find that the ground under them has been eroded by mistrust and fear, we will not get another chance, for at least a generation, to find the way forward toward peace in the Holy Land. That is why it is so important that both societies, and Americans who support peace, must be engaged now - before the opponents of peace get the upper hand.