On the television screen next to Rep. Jerry F. Costello's desk, President Bush flashed anger over the outcome of yesterday's Persian Gulf talks. But for the Illinois Democrat, world politics has become very personal -- and very scary.

Costello was talking about his 21-year-old son and namesake, who is a private first class stationed with the 82nd Airborne Division near the Saudi border with Kuwait. If war comes, Costello's son is likely to be one of the first in action.

Costello spoke quietly with no anger. He measured his words and took great care to offer praise for the parts of the president's policy he agrees with. But as he talked on, Costello became ever more clear about the agony he faces in having to vote up or down on a war in which his own son's life will be at stake.

"I can tell you this," he said, "that if every member of Congress had a son or daughter in the Middle East, if the president had his son or his daughter in the Middle East in combat now, it might change their attitude to some extent when it comes to the issue of either war or pursuing options that take patience and time."

Costello said he expects to vote against war and for giving sanctions more time to work. "It's very difficult for me as a parent and as a member of Congress to risk either my son's life or the sons and daughters of other families in my district and around this country," he said, "when I know that in a matter of months that we can accomplish the same results without jeopardizing American lives."

In Congress, only Costello and Rep. E "Kika" de la Garza (D-Tex.) have sons or daughters with the U.S. military forces in the gulf region. De la Garza, who was out of town yesterday, has a 34-year-old son, Jorge, assigned to the gulf as a Navy surgeon to support the Marines in the Middle East. Costello's son, Jerry, is a paratrooper who has already packed up his personal effects and sent them home, to be ready for battle.

The last time Costello talked to his son was on Sunday. "He said that he had unlimited time to talk, which was pretty unusual," Costello said. "He indicated to us that it would probably be the last time that he would be able to call home until after Jan. 15. He had been given orders to box up all of the letters and personal things he had received from his family back in the states." All he'd have left was his rucksack.

"He very clearly indicated to me that they were beginning to move, to become mobile," Costello said, adding with both pride and unease that his son was in a "first-strike unit."

Costello's wife initially opposed their son's decision to take leave from college and enlist in the Army. "She had my assurance that the threat of the Cold War was almost over, that this would be the best time," he said with a sad chuckle over his political miscalculation, "that I doubted very much that he was going to see combat."

But Costello said his son bore no bitterness. "He told me, 'Look, I think things are going to be fine, don't worry about me. Along with my commitment when I signed on the dotted line to be with the Army and serve our country for two years comes responsibility. That responsibility means that if they call you into combat, you go.' "

Costello said he admires his son's attitude but worries about what he might be fighting for -- wondering, for example, if restoring the emir to power in Kuwait is a worthy goal. "I'm not sure that we should be willing to spill American blood in the sand to restore a monarch," he said.

He said he also was disturbed during a visit to the Middle East to see so many young Saudis away from the front lines. "In Riyadh, I saw many young men who were walking the streets at night," he said, "and I couldn't help but think of my son who is 21 years old who's here defending their country and their well-being. Why were they not in uniform defending their families and their country?"

Costello is a surprising politician to be saying these things. This is no peacenik or radical. A veteran of local politics in southwestern Illinois, he has the square build and moderate politics of a loyal organization Democrat. "I probably have supported the president more often than not on foreign policy and defense issues," he said.

But this time is different, and though Costello said he'd like to think his son's presence in a danger zone has not destroyed his objectivity, he freely acknowledges that he sees this issue differently from others. "There's not a half-hour that goes by when I don't think of him and the situation in the Middle East. It's probably the most crucial decision I'll make in my public career."

And as a father.