From inside a former Lowe’s store in Anderson, S.C. National Guard soldiers keep their eyes on flat-panel computer monitors, watching for any air attack against the United States.

Responsibility for that mission, called Operation Clear Skies, was assumed recently by the Guard’s 263rd Army Air Missile Defense Command, based in Anderson. That duty had been performed by a regular Army unit, the 32nd Army Air Missile Defense Command at Fort Bliss, Texas.

“This is a very prestigious mission for us,” state Adjutant General Stan Spears said.

The mission has grown since the Sept. 11, 2001, attacks. Initially, it covered only command and control of air defense artillery units that ring Washington, D.C. Now it involves planning and defending against any low-level airborne attack, such as the terrorist strikes against New York and Washington in 2001.

That includes protecting events, such as a state funeral, that draw national leaders and foreign dignitaries, said Maj. Gen. Harry Burchstead, the Guard’s deputy adjutant general, who doubles as commander of the 263rd.

Also, the 263rd would be called in to help plan a defense against airborne attacks on major national events such as a political convention.

The assignment suits the 263rd. Its operations are contained in a series of tents that can be packed into Humvees and trucks and hauled anywhere at a moment’s notice.

The 263rd is one of only three such U.S. military units. The other two are in the active-duty Army. One handles air defense for the Pacific area. The other is assigned to U.S. Central Command, which commands U.S. military units in Iraq and Afghanistan, among other places.

From Anderson, the S.C. unit commands three Patriot missile battalions and one short-range air defense battalion, the Avenger Air Defense System.

Burchstead said 40 soldiers work full time in the operations center. Six more were mobilized when the Guard assumed the mission.

The 1st Air Force, which might have to scramble fighters to intercept a hijacked airliner, also is involved in the Clear Skies mission.

The nation’s air defense system itself has come under scrutiny. Efforts to thwart the Sept. 11 terrorist attacks seemed to fall through the cracks, investigators for the 9/11 Commission found.

The 263rd’s mission is part of the U.S. Northern Command, created in 2002. It is responsible for the defense of Canada, Mexico and the United States — except Hawaii. The command also includes the North American Aerospace Defense Command, or NORAD.

A joint effort of U.S. and Canadian militaries, NORAD radar and satellites keep an eye on the airspace over Canada, Alaska and the continental United States.

Having the National Guard handle the nation’s air defense mission makes sense, commanders said.

“I think it’s significant from the aspect that we’ve come full circle of where we were,” said Brig Gen. Francis Mahon, commander of the 32nd Army Air Missile Defense Command. “You go back to the Cold War, the early era, the National Guard was integral for the defense of the homeland.”

Spears expects the mission will be handled in Anderson for “as long as NORAD needs it.”

The National Guard Bureau contributed to this report. Reach Crumbo at (803) 771-8503.