President Bush and Mikhail Gorbachev led European leaders Monday in signing a historic treaty that slashes non-nuclear weapons in Europe and pushes the Cold War deeper into history. "What a long way the world has come," exulted the Soviet leader.

Scarcely had the accord been signed when Bush sought to cement European support for the continued effort to force Iraq's withdrawal from Kuwait. "Our success here can be neither profound nor enduring if the rule of law is shamelessly disregarded elsewhere," he said in a speech to a 34-nation summit called to discuss European security in the post-Cold War era.Gorbachev followed Bush to the podium, and he, too, blended words of praise for East-West cooperation in Europe with the need to halt Iraq's aggression.

"We're prepared to show patience in the quest for a political solution, but we remain firm and determined in implementing the will of the United Nations," which has demanded Iraq's withdrawal, he said.

The two men spoke after a glittering signing ceremony in an ornate ballroom at the Elysee Palace. The long-sought agreement to destroy tens of thousands of tanks, artillery and armored combat vehicles in Europe is the most sweeping arms accord in history. It will alter the military balance in Europe by erasing Moscow's ability to mass huge numbers of tanks and other heavy armor in central Europe.

"It is the farthest-reaching arms agreement in history and it signals the new world order that is emerging," Bush said beforehand. "This reduces to practically nil the tensions that have existed."

The leaders also signed a companion non-aggression declaration between the 16 nations of NATO and the six nations of the Warsaw Pact, which is disintegrating as a Soviet-led mililtary alliance.

It pledged that the nations "are no longer adversaries, will build new partnerships and extend to each other the hand of friendship." The document also asserted that the countries have an "obligation and commitment to refrain from the threat or use of force" against each other.

Gulf crisis on leaders' minds

It was clear from the outset that the Persian Gulf crisis was on the minds of many leaders, and from the Iraqi News Agency came word that Saddam Hussein had ordered an additional 250,000 troops to Kuwait, more than doubling its military strength there.

In his speech, Bush saluted those who have made it possible for Europe to end "decades of repression to rediscover their birthright of freedom."

In hailing the conventional arms treaty, he also looked ahead to an "open skies" agreement permitting reconnaissance flights to check compliance with arms agreements.

Then he took an abrupt rhetorical turn to the Persian Gulf, where he said the principles of democracy and freedom that guide the new Europe "have been violated." Recalling that he and Gorbachev have issued a joint call for an Iraqi withdrawal, Bush said, "Can there be room for any other view? . . . (These) principles have no geographic limits."

Gorbachev noted that the signing marked the fifth anniversary of his first superpower summit with former President Reagan. "What a long way the world has come," he said.

He looked ahead to negotiations still to come. He said the Soviet Union is willing to begin negotiations on reducing arsenals of short-range nuclear weapons within a month or two.

"Instead of military force, our world order will be based on equitable dialogue," he said.

10,000 police provide security

With the extraordinary assembly of government leaders, French authorities mobilized rooftop sharpshooters, anti-terrorist units and 10,000 police officers to provide security - and also to clear paths for convoys of limousines. Parisians braced for severe traffic disruptions.

The leaders of the NATO members, six Warsaw Pact countries and 12 neutral nations proceeded from Versailles to the Kleber International Conference Center to officially open the three-day summit on European security.

Officials said Bush would seek backing for a United Nations resolution authorizing military action to force Iraq out of Kuwait.

In another round of diplomacy, Bush planned to meet over dinner with Gorbachev, their fourth meeting in less than a year. The Persian Gulf was one likely topic of discussion. Another was U.S. assistance to the embattled Soviet leader, struggling against economic difficulties.

"We would always be open-minded on humanitarian aid if there's a real need there," Bush said.

Later, Bush will fly to the Middle East for a Thanksgiving Day visit with U.S. troops in Saudi Arabia.