DHAHRAN,SAUDI ARABIA — DHAHRAN, Saudi Arabia -- As the war against Iraq enters its second week, U.S. commanders in the field are expressing concern that Iraq may be reserving the bulk of its air force for use in a ground war that they predict will be more difficult than they originally assumed.
Their concerns reflect in part continuing frustration due to weather conditions, including dense morning fog and daytime cloud cover that have occasionally hampered bombing runs as well as reconnaissance missions for determining whether targets have been destroyed.
"It is a little frustrating when you go up to the target area and you can't see the ground," Col. Ervin C. Sharpe, commander of an air base in Saudi Arabia, told pool reporters. He hinted that the Air Force was having to adjust its timetables for destroying targets and that the next stage of the conflict would be delayed until there was greater certainty about results of the raids.
"You can't set a timetable on war," he said. "You have strategic objectives, and you go after those objectives, and you meet them as quickly as you can."
Commanders in the field generally have expressed more pessimism than have their military and political chiefs. Defense Secretary Dick Cheney and Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, said yesterday that the operation against Iraq remained on schedule, while cautioning that Iraqi President Saddam Hussein could try to take the initiative in the air or on the ground.
Iraq has been able to keep the region in a state of high anxiety by launching unpredictable barrages of Scud missiles. Two Scuds were launched against Dhahran late last night, Saudi officials said, and residents heard the loud boom of Patriot batteries being fired and intercepting the Iraqi missiles. There were no reports of injuries.
Military officials acknowledge that their work is likely to be complicated by Iraq's finding ways to undo some of the damage that is being done. There is in particular worry that Iraq may be able to quickly rebuild bombed runways, allowing it to use its air force of more than 700 planes if a ground war begins.
"Runways are very, very difficult to take out," Air Force Lt. Col. Mike Scott said at a briefing in Riyadh, the Saudi capital. He said that raids against airstrips would continue and that they would force Iraq to "repatch, repatch and repatch."
Pilots say the few Iraqi aircraft that have been in the air avoid close engagements, sometimes firing missiles but veering away before pilots can guide them to a U.S. plane.
Colonel Scott said allied warplanes have flown 12,000 sorties against Iraq, half of them combat missions and half support missions, including refueling and reconnaissance. About 15 percent of the total have been flown by planes from countries other than the United States. He said planes from the Persian Gulf state of Qatar participated Tuesday for the first time.
Some of the latest raids have been carried out by France, whose fighter-bombers attacked Iraqi targets in Kuwait yesterday and Tuesday.
Colonel Scott meanwhile reported the largest ground skirmish so far between U.S. and Iraqi forces, although the exact place and time of the clash was not disclosed. He said a patrol from the 3rd Armored Calvary encountered Iraqi soldiers inside Saudi Arabia and, apparently after firing shots, took six Iraqis prisoner.
Two Americans were slightly injured in the clash but were able to return to their units, he said.
Army commanders are bracing for larger and more protracted battles.
Officers in several armored units say the United States would begin a major ground offensive by sending helicopters to attack Iraqi tanks, and only then moving forward with large numbers of troops.
Army Lt. Col. Bill Reese, commander of a cavalry squadron with helicopters and tanks, said that regardless of the number or effectiveness of allied air attacks, significant Iraqi forces would be waiting in Kuwait.
"While I think the bombing campaign is going to really hurt them, I've told my guys very clearly: Don't think this is going to be a cakewalk where we walk into the country and they're going to throw their hands up and surrender because we've bombarded them into the Stone Age," Colonel Reese said.
He said he expected strong resistance from Iraq's elite units, the Republican Guards. "We're going to have to go over and very calculatedly destroy them," the colonel said. "We're going to have to engage in many battles of direct fire."