Ready to Talk, Bush Says; Will Defy Iraq on Embassy Closure : Gulf crisis: The President calls up reserves and rejects preconditions for negotiations. The world cannot waver, he declares.

President Bush on Wednesday called tens of thousands of military reserve forces to active duty and declared that although the United States is “prepared to talk” to Iraq, U.S. officials will refuse to negotiate under Iraqi “preconditions.”

“The United States won’t be threatened,” Bush declared, rejecting Iraqi President Saddam Hussein’s demands that American troops be withdrawn from Saudi Arabia before negotiations can begin on the freeing of U.S. hostages held in Iraq and Kuwait.

With the strain of the three-week crisis clear in his lined face and testy demeanor as he answered questions during a 25-minute news conference, Bush acknowledged that he worries about the fate of the hostages but insisted that “the world simply cannot waver” in resisting Iraq.

“Any decision maker in the United States or in any of these countries is concerned about the lives of innocent civilians--innocent people,” Bush said.

“You weigh that very thoroughly against your actions,” he added, but “international law” and the sanctions against Iraq “must be enforced.”

Bush said U.S. diplomats will continue to seek explicit U.N. Security Council approval for a military blockade of Iraqi ships. But even without U.N. action, he said, “we have all the authority we need” to stop shipments of goods to and from Iraq.

In an attempt to bolster domestic support for the Middle East operation and to rebut charges by Hussein that the United States is his principal adversary, Bush repeatedly emphasized the international nature of the anti-Iraq effort.

“This is not a matter between Iraq and the United States of America,” he said, “It is between Iraq and the entire world community.”

All the major nations of Europe, he noted, have joined the United States in rejecting Iraq’s demand that embassies in Kuwait be closed by noon Friday--a deadline that could become the newest flash point in the continuing gulf standoff.

Military forces from 22 nations have joined U.S. soldiers and sailors in the Middle East, Bush said. They include several Arab states--Saudi Arabia, Egypt and Syria primarily--as well as most of the nations of Western Europe. Many of the contingents, however, are small and are present more as a symbol of allied resolve than as major fighting forces.

Administration officials acknowledged they are worried that if the crisis becomes a long stalemate, Hussein might succeed in rallying more Arab support by portraying himself as a victim of American demands.

That concern is shared by many private Mideast experts as well. A U.S. oil company executive who has been consulted by Administration officials said he believes Iraq’s strategy now is to “do nothing if the U.S. stops or damages one of its tankers because they think this would be very damaging to the U.S.” among Arab nations.

“They think it would undermine (President Hosni) Mubarak in Egypt and create problems for the royal family in Saudi Arabia if the U.S. appears to be the aggressor,” the executive said. “So their strategy seems to be to play for time in hopes the Arab world becomes more radicalized.”

The executive said he also has been told by Iraqi officials that Iraq has mined the Kuwait city harbor and wired explosives to Kuwait’s oil-field installations.

“They say if the United States invades Kuwait they’ll leave it a desert wasteland,” said the executive, who speaks almost daily with Iraqi officials. He agreed to be interviewed on condition he not be identified.

Rumors that Iraq had mined the harbor and wired explosives to the oil-field installations swept the American intelligence community Wednesday. A key government intelligence source said the United States “has no information to confirm the rumors” but also is in no position to deny them.

The Pentagon announced that it was sending four Navy minesweepers to the Persian Gulf. The four ships--the Adroit, Leader, Avenger and Impervious--are being ferried to the Middle East aboard the commercial ship Super Servant Three.

The Transportation Department, meanwhile, announced that 40 retired merchant ships have been activated to haul supplies and weapons to support the Middle East deployment. The ships, part of the 96-ship Ready Reserve Fleet, will sail from Suisun Bay, north of San Francisco; Norfolk, Va.; Beaumont, Tex., and several other ports, officials said.

Thirteen of the ships already are at sea, 12 are being prepared for sailing and 15 more have been called up for duty next week, officials said. The ships are crewed by civilian mariners from union rolls.

Defense Secretary Dick Cheney confirmed that the United States will be selling advanced F-15 fighter planes to the Saudis. Washington initially will sell C- and D-model F-15s from existing inventories, Cheney said. More advanced F-15E models will be part of the “long-term package,” he said.

The solid allied support for the U.S.-led effort has been a major theme for Bush and other Administration officials, who are well aware that many Americans have doubts about sending U.S. troops to defend oil supplies that are more vital to Europe and Japan than to America.

The need to keep that support, however, has required intensive diplomacy, including the continuing effort to persuade the United Nations to endorse the use of military force to stop Iraqi shipping. Secretary of State James A. Baker III spoke with Soviet Foreign Minister Eduard A. Shevardnadze about that issue Wednesday, Bush said.

Another key concern within the Administration involves the setting of Bush’s remarks--his vacation home in Kennebunkport, Me.

For Wednesday’s news conference, White House advisers had Bush wear a suit and tie--something he usually does not do here--and stand flanked by Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, and Cheney, both looking stern and businesslike.

The three men were placed in front of Bush’s house, a relatively drab background, rather than the usual setting for news conferences at the Bush vacation home--a lawn overlooking the sparkling ocean.

The effort to project a businesslike image was only partially successful, however, as Bush’s dog, Millie, played around his feet while he spoke.

In any case, Bush was as insistent as ever about his right to a vacation. “I’m going to keep using my boat, and I hope the rest of America will prudently recreate,” he said.

Bush was responding to questions about the need to conserve energy as a result of the disruption of oil shipments from Iraq and Kuwait. The President said conservation is warranted, but he added that he sees no reason to fear an oil shortage at this point.

“I think it is a good time to conserve, so I’m glad you reminded me of that, and (I) would call upon Americans to conserve,” Bush said. “That doesn’t mean that life screeches to a halt.”

Yet another political issue facing the Administration involves the reserve call-up itself.

Since the end of the Vietnam War, the military has assumed that in the event of a major mobilization of forces, reserves would be called up. Many support functions, from laundry to cargo handling, have been delegated by the services, particularly the Army, to reserve units.

The reserves “are an integral part of the total military command,” Bush said as he announced the call-up of thousands of Army, Navy, Air Force, Marine Corps and Coast Guard reserves and Army and Air Force National Guard units.

At the same time, a substantial reserve call-up is likely to cause a noticeable disruption of civilian activities. Because of that, the move has been a subject of extensive discussions within the Administration. Military officials had asked for a larger call-up, Pentagon officials said, but were overruled by civilian officials.

As it is, the reserve mobilization, which will focus on doctors and nurses, construction workers, truck drivers, airlift workers and intelligence specialists, is the first in two decades and potentially the largest since the John F. Kennedy Administration. About 40,000 men and women are expected to move into active military duty within 10 days, with a possibility of more being summoned as the crisis continues, Administration officials said.

Many of the activated reserves will remain in the United States, but at least some will be sent to Saudi Arabia, the Pentagon said in a statement.

“These reservists will support Operation Desert Shield by joining active-duty units deployed in and around the Arabian Peninsula or by filling critical military support vacancies in the United States or elsewhere,” the Pentagon said.

The last reserve mobilization occurred in 1970, when President Richard M. Nixon called 26,273 reserves to active duty to deliver mail during a postal strike. Presidents have called up the reserves 10 times since World War II, including a deployment of more than 100,000 reservists by Kennedy during the Berlin crisis, and a call-up of 35,000 by President Lyndon B. Johnson during the Vietnam War, the last time reserves were called to potentially face potential hostile fire.

Staff writers Jack Nelson and John M. Broder, in Washington, contributed to this report.