The Hamas takeover of the Gaza Strip changed many perceptions and dynamics in the region. But it is also the constants that must be borne in mind by the Olmert government in Israel as it enters into closer cooperation with Mahmoud Abbas and the Fatah-led West Bank. First and foremost, Hamas is a dedicated Islamist organization with close ties to Iran. It represents Islamist objectives that are totally antithetical to Israel’s values as well as those of moderate secular Arabs in Palestine, Egypt and Jordan. If Israel boycotted Hamas prior to the Gaza takeover, it has all the more reason to do so today, with the sole exceptions of humanitarian aid, prisoner exchange and a ceasefire. On the other hand, both Fatah in the West Bank and Hamas in Gaza continue to believe firmly in the unity of the two territories. Israeli Prime Minister Ehud Olmert will never be able to negotiate a permanent-status agreement with Palestinian President Mahmoud Abbas about the West Bank alone. Nor is the Hamas-Fatah political estrangement necessarily a permanent feature of the new landscape. There is sentiment in Riyadh and some inclination in Cairo to yield to Hamas’ entreaties and try and put a Palestinian unity government back together. Yet the Hamas takeover in Gaza and the Fatah reaction also reflect strong and clearly incompatible core elements, Islamist and secular, in both camps. Moreover, Hamas’ new political and military concentration solely in Gaza in some ways makes it an easier target for a regional secular coalition seeking to isolate and weaken it. Ongoing Palestinian devotion to West Bank-Gaza unity is not the only reason that Olmert-Abbas talks, like those that took place on Monday in Sharm al-Sheikh, cannot in the short term produce an Israeli-Palestinian peace. Both leaders are weak; Abbas’ leadership problem was particularly evident in the Fatah collapse in Gaza. Since then he has displayed a tougher side toward both Hamas and Fatah’s own armed gangs in the West Bank. Certainly he is Olmert’s only conceivable ticket to a Palestinian and regional “agenda with which to prove the Israeli government’s viability. Hence, the Abbas-Fatah-West Bank-centered track may, by default, provide a useful avenue for regional diplomatic activity. However, this is only true if Abbas, Olmert, President Hosni Mubarak of Egypt and King Abdullah of Jordan are willing and able to take certain vital preliminary steps. In order to have any chance at all of success, Abbas must consolidate security control in the West Bank by a single Fatah-Palestinian Authority force in much the same way that Hamas has cleared the streets of Gaza of armed militias. He must reform his own movement’s leadership institutions by replacing the “dinosaurs from Tunis with new blood. And, at least for now in view of his weakness, he must resist the temptation of a renewed unity government. Ehud Olmert can help him by permitting the training and arming of forces loyal to Abbas and by releasing funds and prisoners, and on Monday Israel said it would release some 250 Palestinians. This could also be the right time for the Israelis to release Marwan Barghouti in order to support the younger generation of Fatah leaders. Mubarak has to seal off Egypt’s border with Gaza much more effectively than Cairo has done so far. Hamas in Gaza must be genuinely quarantined if its military buildup is to cease and the threat it poses to Israel and Fatah – as well as to Egypt itself – is to be brought under control. And King Abdullah of Jordan has to offer closer economic, political and security support for Abbas’ consolidated regime in the West Bank. The objectives of this coordinated effort should be modestly and realistically defined, and unrealistic illusions and delusions dispelled. Both Abbas and Olmert know that it was not the absence of a peace process that brought about Hamas’ rise to power, but Fatah corruption and disarray. Thus there will be no new and dynamic peace process, no Jordanian-Palestinian union, no strategic wedge driven between West Bank and Gaza Palestinians, and no international force sealing or quarantining the Gaza Strip. Rather, we can aspire to Israeli-Palestinian success in creating new tools for confidence-building and conflict management. Perhaps, under the best of circumstances, a new phase of Israeli withdrawal from additional West Bank territory can be contemplated sometime in the next two or three years. If all parties concerned, with Washington’s and Brussels’ backing, can stay focused on such limited objectives, they may have a chance to succeed despite the risks involved. And risks abound. For Israel, the danger of releasing funds and prisoners and facilitating Palestinian security activity in the West Bank is considerable but nevertheless manageable. Abbas and Fatah risk being branded by Hamas as collaborators. Both sides have dealt with similar risks in the past – and ultimately failed. Today, hopefully, they are both wiser and more desperate, if only because they are running out of alternatives. This is the default option for getting back on track toward an eventual two-state solution that will include Gaza. Olmert and Abbas – both survivors despite their mediocrity – are the default leaders. If they fail to register even modest progress, we may all end up confronting radical and potentially less friendly options. Yossi Alpheris a former director of the Jaffee Center for Strategic Studies at Tel Aviv University, and was a senior adviser to Prime Minister Ehud Barak. This commentary first appeared at bitterlemons.org, an online newsletter publishing contending views of the Israeli-Palestinian conflict.