WASHINGTON -- His mission is to sell peace in a land riven by war, to bring hope to two peoples accustomed to despair.

The effort alone will make history.When President Clinton travels to the Middle East next week, he will break new ground simply by stepping on old ground. He will become the first president to set foot in Palestinian-controlled territory and to address a group of people whom much of the world has shunned. On his fourth trip to Israel -- a presidential record -- he will push a peace initiative that many Jews believe imperils their homeland and endangers their children.

Every step of the way, there will be diplomatic land mines. So sensitive is this region to symbolism that even Clinton's mode of transportation has stirred up controversy: Palestinians want him to fly Air Force One to their new airport in the Gaza Strip; Israelis would prefer he park that beacon of power near Tel Aviv.

"We don't want added symbolism," said Avi Granot, a spokesman for the Israeli Embassy in Washington.

Behind the presidential emblems, though, is a message, one that never has been delivered directly and simultaneously on the doorsteps of Palestinians and Israelis. It is to stick with the efforts toward peace in the face of terrorism and threats, to work against setbacks because, as White House spokesman David Leavy said, "the alternatives are more violence, more chaos, more loss of life on both sides."

Whether Clinton's message will resonate is anyone's guess. Violence has escalated in recent days, and police are bracing for more riots.

Still, the mere notion of the president's visit already is reverberating among Israelis who have seen him before and, perhaps more acutely, among Palestinians who never dreamed they would.

"I remember when you couldn't say the word 'Palestinian,"' said James Zogby, president of the Arab American Institute in Washington. "Today, the president is going there, meeting with the leaders and speaking with the people. That to us is cause to celebrate."

Not only will Clinton meet with elected and appointed Palestinian officials, starting with Chairman Yasser Arafat, but he could find himself face-to-face with known terrorists, according to U.S. officials. Hundreds of Palestinians, including members of several organizations on America's list of terrorists, will be invited to join the president at a meeting in Gaza aimed at formally revoking calls for Israel's destruction.