President Bush says he will stay the course in Iraq, vowing not to pull American troops out of the country despite an increasingly dangerous situation where American soldiers are being killed almost every day. It was 20 years ago this month that another American president vowed not to pull troops out of another Middle Eastern nation, Lebanon, where hundreds of Americans were killed as well. But the United States has much more at stake in Iraq than it did in Lebanon two decades ago.

After another wave of deadly bombings in Iraq, President Bush could not have been clearer in his message of resolve about the U.S. commitment not to let terrorists drive the United States out of the country.

"It's a pretty clear strategy to me and this country will stay the course. Terrorists want us to leave and we're not leaving," he said.

Nearly 20 years to the day, former President Ronald Reagan offered the same commitment after more than 240 American Marines were killed by a suicide bomber during the U.S. military mission in Lebanon. He as well vowed America would not abandon its duty to the world.

"The reason they must stay there until the situation is under control is quite clear. We have vital interests in Lebanon and our actions in Lebanon are in the cause of world peace," he said.

But within months, the terrorist attack had precipitated the withdrawal of U.S. troops from that Middle East nation. Lebanon's civil war raged for another decade.

Robert McFarlane was President Reagan's National Security Adviser at the time a terrorist truck bomb exploded outside the Marine barracks in Beirut in October, 1983. "I think in terms of U.S. national interests that what we face in Iraq today is far more important than the stakes in Lebanon 20 years ago," he said. "However, the circumstances in terms of how the U.S. government functioned was much different in those days as well. In '83, the withdrawal of American forces really was brought on by the dysfunction between the secretaries of state and defense who disagreed fundamentally on whether we ought to be there in the first place. That isn't the situation today."

Secretary of State Colin Powell was a general serving as the top military adviser to then Defense Secretary Casper Weinberger at the time of the Lebanon bombing. He wrote in his autobiography, published in 1995, that foreign policy cannot be paralyzed by the prospect of casualties, but at the same time, lives cannot be lost unless there is a clear reason why.

"Americans, contrary to myth, do not turn tail and run when casualties arise," said American University historian Allan Lichtman. "However, there does come a point when the casualties do not seem to be worth the mission because the mission is unclear and the mission does not seem to be achieving its objectives. What was at stake in Lebanon was not worth the cost in American lives. So far, Bush has clearly said what is at stake in Iraq is worth the cost of these American lives and perhaps many more."

And to emphasize that point, a top White House official says President Bush's message of resolve was meant as much for Americans as it was for Iraqis who may be wondering whether on-going U.S. casualties could end up shaking the American commitment to rebuild their country.