UNITED NATIONS — Arab leaders allied with America are reportedly concerned that progress in Israeli-Syrian diplomacy will harm peace talks with the Palestinian Arabs.

With Prime Minister Olmert making an unscheduled visit to Amman yesterday for talks with King Abdullah, Al-Jazeera reported that Jordan, Egypt, and Saudi Arabia are worried that the increasing contacts between Israel and Syria might come at the expense of negotiations between Israel and the Palestinian Authority.

In the past, Israeli diplomats are said to have used the specter of reopening peace talks with Syria as a way to lean on Palestinian Arab negotiators. “One reality is clear,” a former Middle East adviser who is now a scholar at the Woodrow Wilson Center, Aaron David Miller, said. Israel cannot “move on two tracks at the same time. It defies logic. It defies history. It defies the Israeli political system.”

Nevertheless, news outlets in the Middle East are abuzz over the reawakening of Israeli-Syrian diplomacy, despite Secretary of State Rice’s plans to meet in London tomorrow with representatives of a steering group known as the quartet — America, Russia, the European Union, and the United Nations — for talks on advancing the Palestinian Arab diplomacy, and despite President Bush’s upcoming trip to Israel.

Some analysts have said Mr. Olmert dangled the prize of renewed diplomacy with Damascus before President al-Assad out of concern that the Syrian leader would resort to violence in the aftermath of last week’s Bush administration report to Congress, which officially confirmed for the first time that Israel’s aerial attack in eastern Syria in September targeted and destroyed a nuclear facility that Syria was building with North Korean help.

Days before the congressional report, Mr. Olmert said in interviews with Israeli press outlets that peace with Syria was possible and that he was working hard to achieve it. According to subsequent reports from Jerusalem, Ankara, and Damascus, Mr. Olmert sent a message to Mr. Assad through Turkish officials. Prime Minister Erdogan of Turkey confirmed those reports, and Syrian officials talked up the renewed diplomacy in Arab press interviews.

Members of the political right in Israel say they are skeptical of both diplomatic tracks. “I don’t think any of these negotiations could currently lead to anything,” the foreign policy point man for the Likud Party, Zalman Shoval, said. In the negotiations with both the Palestinian Arabs and the Syrians, offers made initially could harm future negotiations, he said.

“The Syrian-Israeli problem is a status quo,” said Mr. Miller, whose new book, “The Much Too Promised Land,” describes his role as a Clinton-era negotiator. He noted the lack of fighting in the Golan Heights — a strategic area that Israel won from Syria in the Six-Day War — for more than 30 years.

On the other hand, Mr. Miller said, Israel’s relations with the Palestinian Arabs “keep changing for the worse.” No progress on that front, he said, could threaten “Israel’s character as a Jewish and democratic state,” which is the chief rationale for maintaining strong ties between Washington and Jerusalem.