RIYADH, SAUDI ARABIA, NOV. 14 -- More then 30,000 feet above the desert, Saudi air force Lt. Malih Alsahli squinted at his computer screen as four Iraqi jet fighters streaked toward the Saudi border.

One by one, the Iraqi aircraft banked about 60 miles from the Saudi border and turned back. The jagged yellow arrows that symbolized the planes slowly began retreating off the computer screen.

It was one round in the high-stakes games of aerial cat-and-mouse played out daily between the Iraqi fighters and their adversaries -- the American and Saudi early-warning planes that ply the Arabian skies, with powerful radar spying over the border deep into Iraq.

In wartime, the Airborne Warning and Control System (AWACS), a flying computer bank that generates enough voltage to light a city of 100,000, would be critical to command and control of the skies. These planes would be part of a vast information network linking the radars of ships, aircraft, missiles and satellites in a master war plan.

As a result of that role, the AWACS program has become entangled in the tensions that are molding potential war plans and redefining U.S. political relationships in this troubled region. The high-technology surveillance plane also is one of dozens of sophisticated military systems that have never been tested in combat.

The AWACS, which is a Boeing 707 crammed with banks of computers and radar screens, is designed to track and identify up to 600 aircraft simultaneously, giving operators enough information to determine whether an approaching craft is friendly or hostile.

But high technology has its limits. Patrolling northern Saudi Arabia today, weapons directors on this Saudi AWACS scrambled their escort F-15 jet fighters to check out an unidentified aircraft plodding south slowly across Syria. After investigation, the fighter pilots reported it was a commercial airliner whose identifying electronic signal was not operating or had not been picked up by the AWACS identification system.

Saudi air force officials said today that Iraqi aircraft have been "flying more" in the aftermath of President Bush's decision last week to almost double the size of the U.S. force in the Persian Gulf.

But Col. Bluwi Aboul Rahman, commander of the Saudi AWACS wing, said that in the three months since the invasion, the Iraqi air force has frequently and dramatically altered its flying patterns "to confuse us."

While the Saudi commander said the Iraqi French-built Mirage and Soviet MiG-25 fighters are usually careful to remain miles north of the Saudi border, aircraft on both sides have accused their adversaries of "painting" their planes with fire-control radars at close range over the last three months.

U.S. journalists were allowed aboard a Saudi AWACS flight for the first time today, with Saudi officials hoping to display their crews' technical capabilities as well as a need for even more of the sophisticated planes. In addition, U.S. military authorities were trying to demonstrate a successful joint command-and-control operation at a time when problems in the overall command system here are receiving increased criticism.

The Saudi government, which won U.S. congressional approval for the purchase of five AWACS planes after a hard-fought battle in the early 1980s, now says it believes that the current threat should convince the United States of the need to sell them a more sophisticated version, a request expected to be opposed by the pro-Israeli lobby in the United States, which closely monitors the balance of military power in the region.

Because the AWACS planes delivered to the Saudis in 1986 are less capable of handling large-scale combat, the airborne monitoring system is likely to become yet another major military function that will be taken by U.S. forces if war erupts.

"The American plane is much more capable," said Col. Tom Bliss, commander of the U.S. AWACS planes deployed here. "We have significantly better communications capability . . . and ours is designed to go offensive."

The American aircraft could also link with satellites and transmit radar images of a Middle East air war back to the Pentagon command center, U.S. officials said.

"The Americans know what we bought in the '80s," the Saudi AWACS commander said. "If technology is improving, I would like to get it."

While many senior Pentagon officials have begun raising new concerns over the battlefield command-and-control plans involving the two dozen nations now involved in Operation Desert Shield, Saudi and U.S. air force officials here claim the AWACS surveillance of the Arabian Peninsula is one of the more cooperative joint efforts.

American and Saudi AWACS teams flew joint missions over the peninsula throughout the eight-year Iran-Iraq war.

Before the invasion, the Saudi AWACS flights were manned solely by Saudis, but four-man American Airborne Coordination Element teams now fly with the 15 Saudi crewmen on the missions because of the added complexity of dealing with the greatly expanded number of U.S. vessels and warplanes.

While most American and Saudi ground forces have not even begun joint battlefield operations, the U.S. Air Force says it has invested almost a decade in training Saudi AWACS operators.

Even so, a U.S. official said that in the last three months they have helped expand the Saudi AWACS system "from a very simplistic concept in terms of strategic defense."

Capt. Mansour Khousaib, 27, a Saudi AWACS weapons director, said he worries about the heat of combat, when "things can be misunderstood and coordination a problem."

He added, "But I know the good guys from the bad guys -- I am ready."