Pentagon should think twice before it cuts ground forces, historians warn.

• Author: Erwin, Sandra I.

What will happen to ground forces after the war in Afghanistan ends has been a parlor game in the Pentagon since President Obama laid out the beginning of the U.S. drawdown.

The Pentagon already has ordered moderate cuts in the force between now and 2016. The Army's active-duty force will come down from 570,000 to 520,000, and the Marine Corps from 202,000 to 186,000. A more drastic downsizing could be in the cards if the nation's finances take another turn for the worse.

For the Army and Marine Corps, the end of fighting may be welcome news. But the conclusion of the conflict also could mark the beginning of another battle, one that ground forces must face, at home, after every war: a struggle for relevance and for resources.

In the wake of every conflict since World War II, ground troops have been declared obsolete. And each time, the prognosticators have been wrong, says military historian John C. McManus.

After a decade of grinding wars in Iraq and Afghanistan, the conventional wisdom is that America will have no tolerance for any more ground fights. Policy makers will take that as a cue that it is now time to shift defense dollars from infantry to high-tech weaponry that can be fired from aircraft or ships, far away from the battlefield.

That would be a huge mistake, says McManus, the author of "Grunts: Inside the American Infantry Combat Experience, World War II Through Iraq." In the book, which examines in detail 10 major conflicts over six decades, he concludes that "foot soldiers," regardless of technological advances in weaponry, end up carrying the day every time the United States goes to war.

Presidents, lawmakers and military leaders consistently fail to learn the lessons of history and, wishfully, presume that every ground war will be the last, McManus says in an interview.

In the dawn of the nuclear weapons age, the accepted view was that ground troops no longer would be needed. Similar prophecies transpired after every major conflict, but the exact opposite has happened, says McManus. The common thread that connects each war, he says, is that ground soldiers have done more than 90 percent of the fighting and dying.

There is a "disconnect" between the reality and what people want to believe, he says. 'Americans constantly have to relearn this lesson" that bloodless wars are not possible. Strategists and policy makers hope that standoff weapons can take over, and that "we can let technology do our dirty work," says McManus...