WADI ARABA, ISRAEL-JORDAN BORDER, OCT. 26 -- Israel and Jordan signed a peace treaty today at this bleak desert border post, putting a formal end to their 46-year state of war and launching what both governments expect to be a broad and warm partnership of neighbors.

The treaty is the first between Israel and an Arab state since the breakthrough with Egypt in the 1979 treaty that grew out of the Camp David accords.

Unlike the "cold peace" with Egypt, which has resulted in few commercial or cultural ties, today's treaty contemplates swift cooperation in tourism, trade, road and rail links, water resources and environmental protection. The two nations threw switches connecting their electrical grids in the southern port and resort cities of Eilat and Aqaba immediately after the signing ceremony here.

For Israel, today's agreement secures the largest part of a long-hostile border and marks a milestone in normalizing a nation accustomed to thinking of itself as encircled by enemies. For Jordan, it comes as a declaration of independence from radical Arab neighbors and ends an estrangement with the West that began in the Persian Gulf War, when King Hussein gave tacit support to Iraq.

President Clinton, who signed the accord as a witness, promised to support the peacemakers against "the forces of terror." He called on the countries of the region to unite against terrorism and extremism that could thwart a comprehensive peace -- a theme he began at dawn in Cairo in meetings with Egyptian President Hosni Mubarak and Palestine Liberation Organization Chairman Yasser Arafat and continued late into the evening in an address to Jordan's parliament.

The treaty resulted from direct talks between Hussein and Israeli Prime Minister Yitzhak Rabin, which were intensified amid -- and in answer to -- a sharp surge of terrorist attacks against Israel. Israeli, Jordanian and U.S. protective services anticipated attempts to disrupt the signing, and the security arrangements were described by Israeli officials as the most extensive in the nation's history.

No disruption was apparent here. About 200 miles to the north, Israeli radio reported mortar fire from southern Lebanon into Israel's Galilee panhandle at about the time the signing ceremony began. No casualties or damage were reported, and Israel returned fire with artillery.

Some 10,000 invited guests and journalists turned out for the treaty signing, held under a blazing desert sun in temperatures nearing 100 degrees. To construct this new border crossing, Israel and Jordan cleared an extensive minefield and laid a road over trenches and tank traps. Barbed wire and old fighting positions remained in clear view of the dignitaries.

Hussein and Rabin both began their remarks with celebratory allusions to religion and friendship.

"Peace be upon you, God's peace," the Jordanian king said in Arabic and then English, describing the phrase as "the greeting with which Muslims and Arabs receive their guests."

"All the children of Abraham will remember {today} as the dawning of a new era of peace," he said.

Rabin began in Hebrew with the greeting used on holy days, wishing joy to the people of Israel and Jordan.

Comparing previous relations with Jordan to the "arid desert" all around him, he said the two nations would "draw on the springs of our great spiritual resources, to forgive the anguish we caused each other, to clear the minefields that divided us for so many years and to supplant {them} with fields of plenty."

Rabin even made a gesture of peace toward his own foreign minister, Shimon Peres, whom he conspicuously had ignored when Israel and Jordan signed a precursor to today's agreement in July. Labor Party rivals of many years, the two men are trying to smooth their rocky relationship in preparation for elections next year. Rabin twice inserted praise for "the foreign minister" into his prepared text, and Peres responded with homage to Rabin's "brilliant leadership."

For many among the witnesses, the signing was bathed in a warm glow of high expectations.

Israeli paratroop Col. Magali Wahabi, who grinned through much of the ceremony, said he served along the eastern border here as an operations officer for many years. "We have been waiting for this day a long time," he said. "It is normal life for a people to have peace."

Noraldin Halaby, a Druze religious judge who watched the treaty-signing with Egypt 15 years ago, said today's accord was more important "because it means that peace will come to all the Middle East." Garbed in full-length black robe and a white cylindrical hat known as a laffa, the 71-year-old cleric said peace with Jordan had been "my dream for 50 years."

Newspaper commentator Nachun Barnea wrote today that the treaty with Jordan represents "the first Arab attempt to enter into a partnership with the state of Israel." A 1983 agreement between Israel and the Lebanese government, then dominated by Christians, was abrogated by Lebanon less than a year later and, Barnea wrote, was "a cruel joke." The Egyptian treaty, he said, was costly and cool, and last year's accord with the Palestinians was "born and lives on in blood." But the treaty with Jordan, he wrote, "was born with a kiss."

Israel and Jordan have not met in combat since 1967. In 1970, when Hussein fought his Black September civil war with the PLO, Israel massed troops in a show of support for the Hashemite monarch. Jordan sat out the 1973 war, when an Arab coalition launched a surprise attack on Israel, and the two nations have had extensive -- if officially unacknowledged -- contacts in the decades since.

The accord's popularity in Israel, where the parliament ratified it 105 to 3, was underscored in comments today by opposition leader Binyamin Netanyahu, who has bitterly attacked the Rabin government's negotiating positions with Syria and the PLO.

"Many of the people here have forded the banks of the Jordan river in different circumstances," he said in an interview. "To cross the Jordan in daylight, in peace, and as tourists, is a wonderful thing. It's a day ripe with hope for a fresh beginning."

Jordanians in general seemed more subdued. The Islamic Action Front, a coalition of seven left-wing and pan-Arab parties in Jordan, is intent on blocking normal relations with the Jewish state, and there were lingering antipathies among Jordanians at the signing today.

Suleyman Qadr, editor in chief of the Jordanian daily Al Rai, called it a "historic day" but said he would not visit Israel or sell his newspaper there until Israel's occupation of Palestinian land ends. "It is not easy to end the hard feelings," he said, and as of now, "it is not settled."

In a joint news conference with Mubarak in Cairo, 12 hours before the ceremony here, Clinton said that he and the Egyptian leader discussed at length with Arafat the need for the PLO to "fully implement" its agreement with Israel, which has moved to completion on only one of six areas. And he reemphasized, Clinton said, "the absolute necessity" of combating the militant Islamic faction Hamas and other such groups.

Clinton said he got "a very firm and unambiguous" commitment from Arafat to combat terrorism "and I am satisfied with the response that he gave. I believe he will attempt to implement it."

In the news conference, Clinton also outlined U.S. efforts to nudge Arafat into establishing financial systems in Palestinian territory that would reassure cautious international donors. He announced U.S. backing for a "properly structured" Middle East development bank, a proposal of the Israelis, and he pledged an additional $75 million in U.S. government backing for private-sector development in Jordan.

Speaking before the Jordanian parliament in Amman -- the first U.S. president to do so -- Clinton lauded Jordan's decision to become the second Arab nation to make peace with Israel. "You have sent a signal to the entire Arab world that peace is unstoppable," he said, to warm applause.