Last month, The Washington Post reported that the Bush administration had entered into a secret agreement with Israel to permit continued construction in areas of the West Bank popularly known as "settlement blocs." The story focused on the alleged agreement (the existence of which administration officials strongly deny), but missed the real point: Secret agreement or not, Israeli construction in and around "settlement blocs" has continued without pause throughout the tenure of President George W. Bush, and continues to this day, with only token opposition from the U.S. So, too, has relentless construction of roads and other infrastructure, to facilitate the expansion of those blocs and integrate them into Israel. So, too, has the entrenchment of a comprehensive "security" regime, sealing off the West Bank from these areas and isolating the Palestinians trapped inside them.

"Settlement bloc" is an informal term. Israel has never formally defined the blocs. Neither the Palestinians nor the international community (including the U.S.) recognize settlements in blocs as having any special status, compared to other settlements. And construction in the blocs is clearly barred under Phase I of the road map, which states: "[The government of Israel] freezes all settlement activity (including natural growth of settlements)."

The real question, then, is not, was there a secret agreement, but rather, why has Israel felt all along that it has special license to keep building in these areas?

One answer can be found in a letter sent by Bush to then-prime minister Ariel Sharon on April 14, 2004. In it, Bush wrote, "In light of new realities on the ground, including already existing major Israeli population centers, it is unrealistic to expect that the outcome of final status negotiations will be a full and complete return to the armistice lines of 1949..." Settler advocates immediately seized on this statement as a quasi-official green light from the U.S. for continued expansion of Jewish communities in settlement blocs.

Since then, opposition to Israeli activities in these areas almost inevitably runs into the argument: "But everyone, including President Bush, knows these places are going to remain part of Israel anyway, so why invest political capital in the issue?"

The answer is simple: If Israel is serious about wanting peace, the future of the West Bank must be left to negotiations, not predetermined by unilateral acts. Today, Palestinian President Mahmoud Abbas is trying desperately to demonstrate to his people that negotiations, not violence, are the route to achieving Palestinian aspirations. Continued settlement expansion - even in blocs - undermines him and his pro-peace position. In doing so, it threatens the two-state solution, and conflicts with the fundamental Israeli need to end the occupation and achieve real peace and security for its people. It also embarrasses the U.S. and undermines its peace efforts, while eroding goodwill toward Israel around the world.

President Bush was probably correct in observing that a final peace agreement will have to take into account the situation on the ground in the West Bank, where 40 years of occupation and government-supported settlement policies have, by design, created a new and complicated reality. Indeed, under the 2003 model peace agreement called the Geneva Accords, negotiated by Israelis and Palestinians (many of whom were and remain senior political figures), the Palestinians agreed to Israel's annexing some settlements in exchange for land swaps of equal size from within Israel proper. This experience illustrated that in the context of serious peace negotiations, Israel will likely get much of what it wants when it comes to settlement blocs. But it won't get everything, in large part because "everything" - like the huge blocs Israel is unilaterally expanding and de facto annexing today - is incompatible with the establishment of a viable, contiguous Palestinian state.

Getting from the current reality on the ground to a negotiated agreement will require mutual goodwill and strong, credible Palestinian leadership. If Israel continues to build in settlement blocs, it will find itself with neither, and will likely lose the best, and perhaps last, Palestinian partner for peace it will see for a very long time.

Last week, during a press briefing regarding Bush's latest visit to the Middle East, National Security Advisor Steve Hadley was asked, for the umpteenth time, to clarify U.S. policy regarding Israeli settlements. His response was unequivocal: "There must be an end to settlement expansion, full stop." No mention of settlement blocs. The U.S. should stand by this message. And Israel, for its own good, should listen.