Both America and Israel face significant risks with the diplomacy that has picked up steam following the successful prosecution of the war in Iraq. Israel is being asked to make concessions that are difficult to reverse in exchange for a promise to end terrorism from a Palestinian Arab leader, Mahmoud Abbas, who has been tainted with terrorism for much of his career. Israel is also being asked to pull its forces out of the Palestinian Arab-populated areas whence suicide bombings have been launched and are no doubt still being plotted. The “road map” increases enormously the costs of going back in should the Jewish state continue to come under attack.

So Prime Minister Sharon was doing the only responsible thing in raising questions about the road map when it was delivered to him by the American ambassador to Israel on Tuesday April 30. His delay had several effects, the most important of which was to improve the road map by filling in some of the fuzzy details. He helped America secure the chairmanship of the monitoring committee that will determine whether the Palestinians are acting with sufficient alacrity against terrorism. It would have been folly to permit either Russia or France* or the United Nations to chair such a committee. But the result places a heavy responsibility on the Bush administration.

The big risk America faces goes to its credibility. Mr. Bush has vowed that he will not treat with a Palestinian state that is not democratic and with a Palestinian leader who is tainted with terrorism. Yet resumption of a peace process will confront America with a constant temptation to look the other way at such provocations as Hamas’ recent reply. The terrorist group said it would agree to cease attacks against Israeli civilians within the 1967 borders while maintaining freedom of operation against Jewish settlers and soldiers — and this only on the condition that Israel cease targeting Palestinian terrorists. In other words, Hamas would be able to continue to kill Jews while Israel would not be able to act to prevent them from doing so.

Mr. Bush and his team will face a constant temptation to seek progress on the peace front at the expense of “small details” like this one. Mr. Bush has stepped out onto a terribly slippery slope. On June 24, the president called for the dismantling of the terrorist infrastructures. He has already compromised on his desire to see a new Palestinian leadership untainted by terrorism, in large part because he preferred to include the other three sides of the Quartet in this effort. As he works toward the creation of a Palestinian Arab democracy he can bear in mind that the democratically elected cabinet that governs Israel has backed his plan by only the thinnest of margins.

*As if to underscore the point, France’s foreign minister, Dominque Villepins, met with Yasser Arafat.