Defense Secretary Donald H. Rumsfeld (search) told sailors and Marines aboard this helicopter carrier Friday that the terrorist attacks of Sept. 11 (search), 2001, could have been stopped if U.S. intelligence had penetrated the small group that planned and carried them out.

"We did not have a source inside the group of people that had planned and executed those attacks," he said during a question-and-answer session with Marines and sailors aboard the USS Essex (search) at port in Singapore.

"Had we had a source inside there, we undoubtedly would have been able to stop it," Rumsfeld said, apparently referring to the Al Qaeda (search) network. "We did not."

Rumsfeld did not mention CIA Director George Tenet, whose retirement was announced Thursday, but said it would have been a "big order" for American intelligence agencies to penetrate every conceivable hostile terrorist organization.

The defense secretary also was asked about the government's recent warnings that a terrorist attack could happen this summer in the United States.

"The threat level suggests a good deal of interest on the part of terrorists in attacking the United States," he said, adding he would not predict that an attack would happen.

Earlier, Rumsfeld told reporters the United States will make fundamental changes in its troop presence on the Korean Peninsula as well as in Europe, where U.S. defenses have stood guard against threats that have disappeared or no longer require such a large force.

"It's time to adjust those locations from static defense to a more agile and a more capable and a more 21st century posture," Rumsfeld said.

Rumsfeld spoke with reporters flying with him to Singapore, the island city-state where he is to deliver the keynote address Saturday at an Asian security conference.

The secretary declined to discuss specifics. But his remarks left little doubt that the first major changes are about to happen. They are coming after months of internal Pentagon calculations about how best to array American forces abroad and after a period of consultations with U.S. European and Asia allies.

Rumsfeld did not mention perhaps the most immediate change: the move of a 2nd Infantry division brigade this summer to Iraq from its traditional posts in South Korea. The Pentagon has not said whether that unit would return to South Korea.

During a news conference aboard an Air Force E-4B modified 747 jumbo jet, which serves as a flying national command post equipped for use in wartime, Rumsfeld spoke on a variety of topics. They included the conflict in Iraq and his hope that more countries would decide to send troops to help the United States stabilize the country.

Rumsfeld chided critics who say the lack of stability raises the possibility of the Iraq war's ultimate failure.

"People who look at it and say, `Oh, my goodness it's untidy and it's ugly and it's dangerous,' ought to look at history. It's always been untidy and ugly and dangerous" when people who are used to being ruled are given a chance to build a democracy, he said.

Some in Asia have expressed concerns that removing 3,600 U.S. troops from Korea for use in Iraq -- and possibly several thousand more at a later time -- would be seen by communist North Korea as a sign of American weakness. Rumsfeld said such an interpretation would be mistaken.

"This country will not weaken the deterrent or the defense capabilities that we have, even though numbers and locations may shift and evolve as technologies evolve and as circumstances change," he said. "We have been for a long time, in effect, where we were when the Cold War ended."

There are about 37,000 U.S. troops in South Korea, about 47,000 in Japan and about 100,000 in Europe.

Rumsfeld flew 22 hours nonstop from Washington to Singapore, with three midair refuelings, to attend the Shangri-La Dialogue. At the international security conference, he is to deliver a speech on U.S. security policy on Asia and the Pacific on Saturday.

The Pentagon chief said he also planned to meet separately with his counterparts from Japan, South Korea, Australia and Singapore, in addition to visiting U.S. sailors and Marines aboard the USS Essex, a helicopter carrier in port at Singapore.

At the Singapore conference one year ago, Rumsfeld sent his chief deputy, Paul Wolfowitz, who spoke repeatedly in his keynote address of "our success in Iraq," about six weeks after the fall of Baghdad.

Wolfowitz referred to the overthrow of Iraqi President Saddam Hussein as "our victory," and while he noted that much work remained to be done, the deputy secretary gave no hint that he foresaw the onset of a bloody insurgency. Since then more than 600 American troops have died in Iraq.

Rumsfeld said he would fly to Bangladesh later Saturday for talks with government officials about their military's possible interest in peacekeeping operations either in Iraq or Afghanistan. He said he did not intend to formally request that they send troops to either country.

Among the more important changes that have occurred in East Asia since Rumsfeld made his only previous visit to the region as defense secretary, late last year, was the Pentagon's decision to break a decades-long tradition of not using Korea-based U.S. troops for combat elsewhere.

The recently announced decision to send 3,600 2nd Infantry soldiers to Iraq -- probably by midsummer -- caught the South Korean government by surprise and reflected a major change in the way the Bush administration views the U.S. role in Korea.

Without tying his comments directly to South Korea, Rumsfeld appeared to be alluding to the anti-American protests that are staged periodically in Seoul when he said, "We want our forces where they're wanted, where it's hospitable."

U.S. and South Korean government officials are due to hold talks next week in Seoul on the future of their alliance. The talks are to include the sensitive subject of further U.S. troops withdrawals.


On the Net:

Shangri-La Dialogue: http://www.iiss.org/shangri-la.php

Defense Department: http://www.defenselink.mil

(Copyright 2004 by The Associated Press. All Rights Reserved.)

APTV 06-03-04 2301EDT