The Pentagon is gearing up simultaneously to bolster the defense of U.S. territory and to expand the U.S. military presence in the Persian Gulf region.

Both are in response to last week's terror attacks, and both require a call-up of the National Guard and Reserve.

The Air Force said Thursday that more than 5,000 reservists had been called to active duty. They include a B-52 bomber unit at Barksdale Air Force Base, La., and a B-1 bomber unit at Robins Air Force Base, Ga., both of which are expected to fly to forward bases in the Gulf area.

Some of the reserves are from fighter units to be used as extra defenders of U.S. airspace.

Defense Secretary Donald H. Rumsfeld said Thursday that although the Gulf is the focus of U.S. deployments right now, the coming fight will look nothing like the knockout punch U.S.-led forces delivered in the 1991 Gulf War.

"What we're engaged in is something that is very, very different from World War II, Korea, Vietnam, the Gulf War, Kosovo, Bosnia, the kinds of things people think of when they use the word `war,' or `campaign,' or `conflict,"' Rumsfeld said.

President Bush made similar points Thursday night in his speech before Congress. Speaking to members of the armed forces, Bush told them why they are being called upon:

"This is not ... just America's fight. And what is at stake is not just America's freedom. This is the world's fight. This is civilization's fight. This is the fight of all who believe in progress and pluralism, tolerance and freedom."

Rumsfeld said the American campaign will not mean the end of terrorism.

"I think what you can try to do is to go after this worldwide problem in a way that we can continue our way of life," Rumsfeld said. "It strikes at our way of life, and while we may not eliminate it completely from the face of the Earth, which we surely will not," it can be better controlled, he said.

The Air Force announced that 5,131 members of the Air Force National Guard and Air Force Reserve have been ordered to active duty. They are from 29 units in 24 states and the District of Columbia.

"No other single action more clearly demonstrates the national resolve than to mobilize the National Guard and Reserve forces of America," said Craig Duehring, the Pentagon's chief of reserve affairs.

Rumsfeld has said he expects 35,500 members of the Reserve and National Guard to be called up.

The Pentagon is repositioning military forces to prepare for action, Rumsfeld said, but would not provide details. Other officials said both active and reserve forces are beginning to move.

The Air Force is sending 100 to 130 aircraft to the Gulf region, a senior defense official said, including fighters and B-1 and B-52 bombers. Also, tanker aircraft began deploying from U.S. bases Thursday to establish an "air bridge" for refueling fighters and bombers as they cross the Atlantic.

The Air Force has fighter aircraft in Saudi Arabia and Kuwait, and the Army keeps a virtually permanent presence in Kuwait with soldiers and war materiel sufficient to equip an additional 5,000 troops.

The Navy's 5th Fleet headquarters is on the Gulf island emirate Bahrain, and it normally keeps one aircraft carrier on patrol in the Gulf year-round. It now has one in the Gulf and one nearby in the Arabian Sea; a third -- the USS Theodore Roosevelt -- left port at Norfolk, Va., on Wednesday en route to the Mediterranean. Each carrier has 75 aircraft aboard and is accompanied by a dozen warships.

Early Friday in Japan, the USS Kitty Hawk, the only U.S. aircraft carrier stationed in the western Pacific, left its port in Yokosuka for an undisclosed location. The carrier has a crew of 5,500 sailors, naval aviators and Marines and typically carries 70 aircraft.

A contingent of about 2,100 Marines also is in the Gulf, and a similar-size unit is headed in that direction.

Army Secretary Thomas White said the Army is participating in the buildup of U.S. forces abroad, and the Army is prepared to conduct "sustained land combat operations." A deployment order Rumsfeld signed Wednesday is only the first step in a bigger plan, White said.

House Speaker Dennis Hastert, R-Ill., said bluntly that a ground war is expected. "We're going to have people on the ground somewhere, sometime and we're going to have to face these people -- go into the shadows where they live and work and take them out," he said Friday on NBC's "Today."

Air Force refueling aircraft began deploying Thursday, including KC-135s from Fairchild Air Force Base, Wash., officials said. Grand Forks Air Force Base, N.D., with KC-135 refueling planes, also received deployment orders. Officials at neither base would offer additional details.