Watching George W. Bush defend his Middle East policies last week by raising the ominous specter of “World War III” if he does not get his way invites a look back at the arc of his presidency since the tragic attacks of Sept. 11, 2001.

There is no doubt that Bush is destined to be remembered for his unrelenting execution of one of the nation’s longest periods of military adventure far from our shores. And despite being in the waning days of his tenure, Bush is seeking to widen the U.S. presence in the Middle East.

The president was no lame duck at his Oct. 17 news conference, delivering a vintage performance full of bravado and reeking with disdain for those who doubt his judgment. Whether up or down in the opinion polls, the president has never wavered in his firm belief that combating terror around the world requires a tough stance that gives no ground to perceived enemies. His ambitious plan for the next phase in the war on terror was clearest when defending his determination to use any means at his disposal to prevent Iran from developing nuclear technologies.

“If Iran had a nuclear weapon, it would be a dangerous threat to world peace,” Bush told reporters at the White House. “We’ve got a leader in Iran who has announced that he wants to destroy Israel. So I’ve told people that, if you’re interested in avoiding World War III, it seems like you ought to be interested in preventing them from having the knowledge necessary to make a nuclear weapon.”

History’s full and final verdict on Bush’s sustained military response to Sept. 11 will be a long time coming and seems mostly dependent on whether the Middle East ends up as a stable region dominated by governments that are friendly to the United States.

Even if that happens, it could take decades.

Many who criticize the war in Iraq compare it to the debacle in Vietnam, where the United States lost a decadelong war against communism in the 1970s. But some 30 years later Vietnam is a friend and trading partner. And American soldiers who once fought there now take their families there on vacation. If Iraq follows a similar path over the next three decades, Bush might not be remembered so poorly.

An earlier verdict on Bush’s Middle East policy will be rendered by the next president. And so far it looks as if both parties might nominate candidates who will not dismantle what Bush has put in place. None of the major Republican contenders would do so. And the leading Democrats, while catering to anti-war rhetoric in their party, have repeatedly ducked questions about when or if they would completely withdraw U.S. troops from Iraq.

Indeed, Sen. Hillary Rodham Clinton of New York even voted for a resolution supporting Bush’s notion that the Iranian Revolutionary Guard Corps is a terrorist organization. This suggests that the Democratic front-runner, if elected president, would maintain the military pressure on Iran, although she criticizes Bush’s rejection of diplomatic overtures.

While it is unlikely that the next president will fully abandon the injection of American power into the Middle East, it is likely that after Bush the United States will attempt to project a friendlier face abroad. In many ways, Bush has served as the nation’s post-Sept. 11 hatchet man.

Much as endangered corporations do when hiring a tough-as-nails “interim executive” to carry out painful layoffs and budget cuts, Bush did the dirty work that Americans wanted done in the wake of the shocking and deadly attacks on our own soil. Who can forget the day he grabbed a megaphone and stood on the rubble of the downed World Trade Center towers, vowing to go after the bad guys?

Americans cheered him in those days. But when the cheering stopped and his poll ratings plummeted, Bush did not change. He kept on doing what Americans had once wanted even after they quit wanting it. Not even a midterm election that repudiated his party or a new congressional majority that opposes the Iraq War has dissuaded him.

Whatever one thinks of Bush, he is at least sure of himself. Covering him I have often recalled the words of a judge I once knew who underscored his rulings by saying, “I am often in error, but never in doubt.”

As the nation gears up to evaluate so many contenders hoping to succeed Bush, chances are that most of the debate will focus on what he has wrought. And for decades to come, he is likely to be remembered as the benchmark for a commander in chief who never gave up — without regard for the political cost to his party or his presidency.

Contributing Editor Craig Crawford is a news analyst for NBC, MSNBC and CNBC. He can be reached at ccrawford@cq.com.