Wally said his son is one of the nicest people anyone will ever meet, who "would not hurt a flea," but he is ready to fight for his country.
He said he told his son: "Don't you be proud and die for your country. You make the other guy die for his country."
Wally said he has not seen, heard or read any evidence that the military planes of the type his son flies - an adapted C-130 - have been involved in the combat in Iraq.
Nathan is co-pilot of an attack aircraft that can fire thousands of rounds of ammunition a minute. He sometimes is in the air for up to 20 hours at a time, his father said.
When Wally watches the television news coverage of the war, he looks for mention of the planes. He also watches for planes in images of the skies over Iraq that are broadcast on television.
Nathan is good about calling home every Saturday night. But the conversations are one-sided because Nathan is not at liberty to say where he is or what work he is doing, Wally said. The family also communicates by e-mail.
In a way, it is better not to hear about what her son's involvement in the war has been, Barbara said.
This is McClure's third mission since joining the Air Force. His two earlier missions were in Afghanistan, Wally said. However, he said, "Afghanistan did not worry me."
Initially, the war in Iraq concerned him more than the one in Afghanistan because the Iraqis have had better anti-aircraft weaponry, he said.
Nathan had some exposure to the military through hearing about his family's connections with the Air Force, Wally said.
Wally was eligible for the draft during the Vietnam war but was not drafted. He did serve in the Air Force ROTC.
Wally's father served in the Air Force in World War II, and Barbara's brother and father served in the Air Force.
After the war, Nathan plans to go back to college to get a degree in engineering, his father said.
Nathan has said he would like to be an astronaut one day, but Wally said his son might settle for work in commercial aviation.