Jimmy McCain, 18, will spend three months in boot camp, followed by a month of specialized training before being assigned to a unit. With 25,000 of 178,000 active duty Marines in Iraq now and 80,000 having done tours of duty there or in Afghanistan in recent years, his chances at deployment to a war zone are high.
"I'm obviously very proud of my son," the elder McCain told Time for a story in editions going on sale Monday, "but also understandably a little nervous."
McCain's communications director, Eileen McMenamin, confirmed the accuracy of the Time story but said the Senator would not comment further Saturday.
McCain, 70, has been an outspoken supporter of the war in Iraq, saying just last month during a Senate debate on a troop-withdrawal resolution that leaving Iraq would "risk disaster."
"Withdrawal and fail, or commit and succeed," McCain said.
McCain said having a son serving in the war would not change his position.
A Republican considered a possible presidential candidate in 2008, McCain served as a Navy pilot and was shot down over North Vietnam in 1967 and held as a prisoner of war for more than five years.
Sen. McCain's father, Admiral John S. McCain Jr., commanded U.S. forces in the Pacific during Vietnam, where he was responsible for air strikes that may have endangered his imprisoned son. His grandfather, Admiral John S. McCain Sr., served in the Pacific in WW II and was present at the Japanese surrender aboard the U.S.S. Missouri.
Another of Sen. McCain's seven children, Jack, 20, just completed his first year at the U.S. Naval Academy in Annapolis.
Sen. McCain said Jimmy was well aware of the family's Navy background but had friends in the Corps, had read about the service branch and "he just wanted to join up.
"I don't think there's anything unusual about Jimmy," McCain said. "There are, thank God, lots of young men and women like him."