Three years into major combat in Vietnam, 28,500 U.S. service members had perished, millions of families were anxious about the military draft and antiwar protests had spread to dozens of college campuses.

Today, at the same juncture in the Iraq war, about 2,400 American soldiers have died, the U.S. military consists entirely of volunteers and public dissent is sporadic.

There's one other difference: The war in Iraq is more unpopular than was the Vietnam conflict at this stage, polls show.

More Americans -- 57 percent -- say sending troops to Iraq was a mistake than the 48 percent who called Vietnam an error in April 1968, polls by the Princeton, New Jersey-based Gallup Organization show. That's because more people believed that Vietnam was crucial to U.S. security, scholars say.

``People simply value the stakes much lower in Iraq than they did in Vietnam,'' said John Mueller, a presidential historian at Ohio State University in Columbus. Vietnam ``seemed vital in terms of the Cold War and stopping the communists. People don't see this as an important adventure.''

The poll numbers suggest that President George W. Bush may come under overwhelming pressure from voters to resolve the war, as did President Lyndon B. Johnson 38 years ago, even though both men vowed to stay the course.