President Obama's speech in Cairo this month reaffirmed the U.S. commitment to resolving the Arab-Israeli conflict, opening a window of opportunity for achieving comprehensive peace. The president espoused a historic vision, and now the onus is on regional leaders to match rhetoric with action.

Israelis, Palestinians, and Arab states all have an obligation to move the process forward and play a role in achieving peace. During a recent trip to Israel, the West Bank, and Turkey, we observed several promising developments that suggest all sides are moving closer to a resolution.

First, there is widespread confidence in Obama and the team he has assembled, starting with former Sen. George Mitchell, the special envoy for the Middle East. Every official we met with welcomes greater U.S. engagement and believes the Obama administration has already served as a catalyst for positive change.

Second, the mission to train Palestinian security forces - led by Army Lt. Gen. Keith Dayton, the region's U.S. security coordinator - has helped build a new foundation for trust between Israeli and Palestinian leaders. To date, Dayton's team has trained 2,100 Palestinian officers, an undertaking that the Israeli defense forces and government view as constructive. Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak both told us that Dayton's team has improved security in the West Bank, and that Israel supports U.S. plans to augment the mission.

Third, in our recent meetings in Washington and Jerusalem, Netanyahu assured us that Israel does not want to govern the Palestinians. Netanyahu has made it clear that he strongly believes in Israelis and Palestinians living side by side in security and peace, and he appeared committed to substantive measures to improve the lives of Palestinians.

In fact, the same day the prime minister met with our delegation, he chaired an inter-ministerial meeting on projects that would boost the economic infrastructure of the West Bank. He expressed a strong interest in improved Palestinian access to commerce, agriculture, water, and tourism - all of which would help lay the groundwork for a future Palestinian state.

Fourth, Syrian President Bashar al-Assad appears ready to improve ties with the United States, engage in peace negotiations with Israel, and play a more constructive role in the region. In response to a recent proposal to establish a formal dialogue to end the flow of foreign fighters into Iraq, Assad agreed to host officials from U.S. Central Command.

Fifth, in the recent Lebanese elections, the pro-Western "March 14 coalition" received more votes than Hezbollah. That served as a clear popular rejection of Syrian and Iranian influence in Lebanon.

Finally, there is growing agreement among regional leaders on the threat posed by Iran. Nearly every official we met with raised the issue of Iran and indicated concern about a potential nuclear-arms race in the Middle East.

In Turkey, Prime Minister Tayyip Erdogan said he would not accept weapons of mass destruction in the hands of Iran. His point was reinforced by nearly every official from the region who has visited Washington.

In addition, Arab leaders are increasingly concerned about Iran's support of violent extremism. In April, Egyptian President Hosni Mubarak took decisive action to stop Iranian-supported Hezbollah cells planning an attack in Egypt.

Rather than dividing the region, Iran now serves as a source of common concern and shared interests.

Obama's speech in Cairo set a tone of hope for the Middle East. It reminded us all of the historic ties that bind Christians, Jews, and Muslims. During our trip to the region, we saw many reasons to believe that peace and security are possible in the near term, and we embrace the president's vision.

Now, all of the region's leaders must take the difficult steps necessary to cultivate an atmosphere of peace, acting on the president's message to build a better future.

Edward E. Kaufman, Robert P. Casey Jr., and Frank R. Lautenberg are Democratic U.S. senators representing, respectively, Delaware, Pennsylvania, and New Jersey. Kaufman traveled separately to Syria, and the observations about that country are his alone.