WASHINGTON (AP) _ The United States can dominate the skies above a battlefield with technology superior to that used as recently as the Persian Gulf War, Defense Secretary William Perry said Thursday.

``The cliche, `We're in a new era,' is really true,'' Perry said in a speech to members of the American Institute of Aeronautics and Astronautics, a private scientific group.

For example, Perry said, a new computerized planning system has dramatically cut the time for plotting the conduct of an air war.

In the months before Desert Storm, commanders used pen and paper to arrange the targets and aircraft used in the air war, Perry said. Last October, when Saddam Hussein's forces again appeared to be threatening Kuwait, a new computerized air campaign planning system was used, and ``it took us three days,'' Perry said.

The Pentagon is ``modernizing our Air Force, but not the way we used to,'' the secretary said.

The end of the U.S.-Soviet superpower rivalry means the U.S. military will not be building any new nuclear bombers after 20 B-2 Stealth bombers are completed; nor will are there any intercontinental ballistic missiles or new nuclear weapons on the drawing boards, Perry said.

Instead, advances in certain technologies are giving U.S. air forces the edge on the battlefield _ not only what the military calls ``air superiority,'' but ``air dominance,'' meaning the opponent is so weakened that U.S. aircraft aren't even challenged.

``We had it in Desert Storm, and we liked it,'' Perry said.

The increased accuracy of laser-guided ``smart bombs'' means that fewer pilots and fewer aircraft need to be put in threatening positions in combat.

The Air Force also has been working on new technologies that will piece together information from satellites, ground forces and other aircraft, to give commanders a live-time picture of the battlefield, Perry said.

Perry pointed out that the F-15 fighter, which was introduced in 1977, had 60,00 lines of computer code in its systems.

The F-22, the new stealth fighter under development by the Air Force, will have 1.6 million lines of computer code, ``more than the space shuttle Challenger,'' the secretary said.

In past years, the Defense Department relied on an industrial base that had the military as its only client. But the post-Cold War shrinkage of the defense industry also means that many advances are coming out of an industry that serves both the private sector and the military, the secretary said.