Last night, President Bush once again urged Americans to take terrorism seriously — a warning that hardly seems necessary. One aspect of that terrible day five years ago that seems immune to politicization or trivialization is the dread of another attack. When Mr. Bush warns that Al Qaeda means what it says, that there are Islamist fanatics around the world who wish us harm and that the next assault could be even worse than the last, he does not need to press the argument.

After that, paths diverge. Mr. Bush has been marking the fifth anniversary of Sept. 11 with a series of speeches about terrorism that culminated with his televised address last night. He has described a world where Iraq is a young but hopeful democracy with a “unity government” that represents its diverse population. Al Qaeda-trained terrorists who are terrified by “the sight of an old man pulling the election lever” are trying to stop the march of progress. The United States and its friends are holding firm in a battle that will decide whether freedom or terror will rule the 21st century.

If that were actual reality, the president’s call to “put aside our differences and work together to meet the test that history has given us” would be inspiring, instead of frustrating and depressing.

Iraq had nothing to do with the war on terror until the Bush administration decided to invade it. The president now admits that Saddam Hussein was not responsible for 9/11 (although he claimed last night that the invasion was necessary because Iraq posed a “risk”). But he has failed to offer the country a new, realistic reason for being there.

Establishing democracy at the heart of the Middle East no longer qualifies, desirable as that would be. Where Mr. Bush sees an infant secular Iraqi government, most of the world sees a collection of ethnic and religious factional leaders, armed with private militias, presiding over growing strife between Shiites and Sunnis. Warning that American withdrawal would “embolden” the enemy is far from an argument as long as there is constant evidence that American presence is creating a fearful backlash throughout the Muslim world that empowers the fanatics far more than it frightens them.

Fending off the chaos that would almost certainly come with civil war would be a reason to stay the course, although it does not inspire the full-throated rhetoric about freedom that Mr. Bush offered last night. But the nation needs to hear a workable plan to stabilize a fractured, disintegrating country and end the violence. If such a strategy exists, it seems unlikely that Mr. Bush could see it through the filter of his fantasies.

It’s hard to figure out how to build consensus when the men in charge embrace a series of myths. Vice President Dick Cheney suggested last weekend that the White House is even more delusional than Mr. Bush’s rhetoric suggests. The vice president volunteered to NBC’s Tim Russert that not only was the Iraq invasion the right thing to do, “if we had it to do over again, we’d do exactly the same thing.”

It is a breathtaking thought. If we could return to Sept. 12, 2001, knowing all we have seen since, Mr. Cheney and the president would march right out and “do exactly the same thing” all over again. It will be hard to hear the phrase “lessons of Sept. 11” again without contemplating that statement.