According to a senior Defense official, on Nov. 18 there were more than 50 incidents of U.S. pilots’ spotting Iraqi fire on the horizon in the no-flight zone. Under the rules of engagement, the pilots leave the area unless directly fired upon, then return for retaliatory strikes elsewhere–one for each incident. “The Iraqi ‘AAA’ [antiaircraft fire] is like a sine wave in the last 30 days, up and down for no clear reason,” says the official. Some days bring no action. “The aircraft aren’t up there looking for a fight,” says Adm. Barry M. Costello. “It’s mostly recon [reconnaissance].”

Aboard the carrier USS Constellation in the Persian Gulf, Marine Lt. Col. Gary Thomas, just back from dropping 2,000-pound smart bombs on Iraqi surface-to-air missile (SAM) sites, says his four-hour mission in an F-18 was not “full-fledged” combat. “The rules of engagement are very strict–they don’t just say, ‘You’re cleared to bomb’,” he says. “And collateral damage is a great concern.” But Thomas says his missions are intensifying: “The number of surface-to-air events has gone up dramatically.”

So far, no close calls. But even before the recent downing of a drone (pilotless aircraft), U.S. planes were at risk. “There’s no doubt they [the Iraqis] would love to bag a trophy” by bringing down a plane with a pilot aboard, Thomas says.

To prepare the battlefield, target selection has expanded in recent months from SAM sites and AAA batteries to so-called nodes in the Iraqi air-defense system, especially the communication links. Capt. John W. Miller, commanding officer of the Constellation, told NEWSWEEK: “We’re degrading their command-and-control down south.” When asked if this was an “exhibition season” war, Miller replied: “It’s the regular season, though not the playoffs.”