It is the cloud that hangs over every American president who sends a substantial military force abroad -- fear of another Vietnam.
But over the last three decades, critics' warnings of a repetition of that disastrous venture proved largely unfounded, because U.S. undertakings were sufficiently brief in Lebanon and Kuwait and relatively casualty-free in Bosnia.
Now, Democratic critics of the U.S. role in Iraq are invoking the V-word again. Sen. Edward Kennedy, D-Mass., called Iraq "George Bush's Vietnam," prompting Senate Republicans to issue a 16-point list "Why Kennedy's Vietnam is NOT Bush's Iraq" and prompting President Bush to tell Tuesday night's news conference "the analogy is false."
The senator's conclusion seems premature. U.S. casualties, while growing, are only 1 percent of those in Vietnam. The U.S. force is far smaller. And it seems unlikely the American presence in Iraq will last as long as the decade-long effort by three presidents in Vietnam.
But while the analogy isn't totally accurate, there are disquieting elements of truth for Bush. The main one is that the U.S. venture in Iraq is beginning to have the same damaging political impact on him that Vietnam had on another Texan, Lyndon Johnson.
Americans backed the effort to halt communism in Southeast Asia -- until it became clear it wasn't succeeding.
The president's principal arguments at Tuesday night's news conference were designed to counter the fact that more and more Americans see the U.S. effort in Iraq, while worthwhile in its intent, as a failure with no clear end in sight.
There are several reasons:
- What Bush and his top aides portrayed as reasonable and achievable -- to overthrow Saddam Hussein and create a democracy -- increasingly looks as tough in Iraq as in Southeast Asia. Bush, like U.S. administrator Paul Bremer, has been unable to say who will assume Iraqi sovereignty on June 30.
- While it didn't start out that way, the struggle in Iraq has shown signs it could turn into the civil war that Vietnam was, though Bush flatly rejected that.
- And the massive U.S. commitment of financial and human resources in Iraq is limiting the government's ability to perform its other duties, as Vietnam did in the late 1960s.
It has stretched the nation's military resources, raising doubts about both the adequacy of current forces and the decision to commit so many of them to Iraq.
About 135,000 U.S. troops are in Iraq, a big part of the nation's combat-ready troops. The top U.S. commander said he needs two more brigades -- about 10,000 soldiers -- and Bush said the commander will get what he needs.
The president said the effort in Iraq is "required by our interests." But critics say that, as in Vietnam, the United States has overcommitted itself in a country that never was vital to national security, draining resources from the real targets of the war on terror, such as Afghanistan.
As with Vietnam, the war has skewed the federal budget, though Bush and his advisers consistently have downplayed and delayed disclosure of the true cost.
Officials say the $87 billion that Congress approved last fall is adequate for this year. But many believe that more funds will be needed this year and that next year's $50 billion estimate is inadequate.
During the Vietnam War, Johnson sought and eventually won approval of a tax surcharge to pay the cost. This administration, wary of asking for any sacrifice, hasn't sought to raise more revenue. It is one reason for a deficit estimated at a record $500 billion this year.
When Democrats sought to pay for the $87 billion by reducing the Bush tax cut for wealthier Americans, the administration led the drive to block it.
All of this is taking a toll on Bush, though he still has time for the situation in Iraq to stabilize.
If it doesn't, his re-election bid could be in trouble.
Carl P. Leubsdorf is Washington bureau chief of the Dallas Morning News.