The magazine's editors chose the nameless soldier to represent the 1.4 million men and women who make up the U.S. military, which led the invasion of Iraq nine months ago and a week ago captured deposed leader Saddam Hussein.
About 130,000 U.S. soldiers remain in Iraq, with others serving in Afghanistan, South Korea, Japan, Germany and elsewhere.
Soldiers were singled out as the top newsmakers of the year because "the very messy aftermath of the war made it clear that the mission had changed, that the mission had not been completed and that this would be a story that would be with us for months, if not years, to come," Time Managing Editor Jim Kelly said.
The selection echoes 1950, the year the Korean War began, when editors picked the American GI for the cover, writing that "it was not a role the American had sought, either as an individual or as a nation. The U.S. fighting-man was not civilization's crusader, but destiny's draftee."
The 2003 Person of the Year package, which hits newsstands Monday, focuses on a 12-person artillery survey unit stationed in Iraq to tell the story of the American soldier. Two Time journalists embedded with the platoon were injured in a grenade attack this month.
Three soldiers with the unit — Marquette Whiteside, Billie Grimes and Ronald Buxton — are shown on the cover.
The magazine glorifies soldiers but not the Bush administration for putting them in Iraq, calling troops "the bright sharp instrument of a blunt policy," and leaving it to scholars to debate "whether the Bush doctrine is the most muscular expression of national interest in a half-century."
The justification for a U.S. military presence in Iraq has been widely questioned, as coalition forces have found no weapons of mass destruction, which President George W. Bush had argued Saddam was stockpiling.
Guerrilla attacks against U.S. and allied forces stationed there have escalated over the months since May 1, when the president declared an end to major combat. More coalition troops died in November than in any other month: 104, including 79 Americans.
"A force intensively trained for its mission finds itself improvising at every turn, required to exercise exquisite judgment in extreme circumstances," the magazine said. "They complain less about the danger than the uncertainty — they are told they're going home in two weeks, and then two months later they have not moved."
The Pentagon has said it expects to reduce the number of American troops in Iraq to just over 100,000 by May.
Time magazine knows the risks first hand. On the evening of Dec. 10, Time writer Michael Weisskopf's right hand was blown off and photographer James Nachtwey was hit with shrapnel when a grenade landed on their humvee as the platoon was stuck in Baghdad traffic.
Weisskopf is recovering at Walter Reed Army Medical Center in Washington, D.C., and Nachtwey is in New York.
In 2001, when then-New York Mayor Rudolph Giuliani was picked as Time's Person of the Year for leading the city's response to the Sept. 11 terror attacks, critics suggested Osama bin Laden should have been featured as the top newsmaker.
Kelly said Saddam was not considered this year because "he was on the losing side of this conflict," and it was unclear how much he was leading the insurgency.
Last year, Time editors selected Coleen Rowley, the FBI agent who wrote a scathing memo on FBI intelligence failures, and Cynthia Cooper and Sherron Watkins, who blew the whistle on corruption at corporate giants Enron and WorldCom.