By his own campaign's reckoning, President Bush is the only one who can keep you and your family safe from terrorists. But this serious claim is confounded by the comic opera that regularly unfolds in the name of national security.

KoKo, the Lord High Executioner in Gilbert and Sullivan's "The Mikado," would feel right at home in America these days. He was the one who declared: "I've got a little list." The Department of Homeland Security also has a little list (in reality, probably a large one), and on that list is Yusuf Islam.

The world knows him better as Cat Stevens, a '70s singer whose ballads charmed a generation before he converted to Islam.

As he used to sing, this is a wild world, but how wild it is for him is a matter of dispute. In the past, he supported the Ayatollah Khomeini's call that novelist Salman Rushdie be put to death for blasphemy. Recently, the United States has come to believe he has connections to terrorist groups.

But if he is a danger to society, the authorities in Britain, our country's staunchest ally, are not aware of it. When Yusuf Islam found himself in trouble for being on that list, British Foreign Secretary Jack Straw complained to U.S. Secretary of State Colin Powell about the incident.

Let there be no mistake: Yusuf Islam or any other foreigner has no special right to come to this country if the U.S. government does not wish it. That principle, however, does not explain or excuse the ridiculous overreaction in diverting his plane -- bound for Washington, D.C. -- to Bangor, Maine.

What did federal authorities think he was going to do? Threaten to sing "Peace Train" over and over until certain demands were met? Here was someone who was traveling with his daughter and had been to the United States several times, most recently in May, when he met with officials of the White House Office of Faith-Based and Community Initiatives to discuss philanthropic work. Couldn't they at least have picked him up when the plane landed in Washington?

The official reaction to this nonsense was to blame United Airlines for failing to check the list properly and to suggest that the system will be better when Homeland Security takes over screening of passengers from the airlines. Massachusetts Sen. Edward Kennedy recently found himself excluded from domestic flights because officials thought his name was on a list.

If only these were rare signs of folly in matters of national security. Unfortunately, USA Today reported Thursday that undercover investigators, testing the system, were able to get weapons and explosives past security screeners at 15 airports nationwide.

Then there is the case of Yaser Esam Hamdi, a U.S. citizen held in solitary confinement since late 2001 as an enemy combatant. He might have been held forever as a virtual nonperson if the U.S. Supreme Court hadn't intervened. Under an agreement to settle the matter, he will renounce his citizenship and be sent back to Saudi Arabia, where he faces no charges.

The obvious absurdity was pointed out by Sen. Patrick Leahy, D-Vermont, who wondered how the Justice Department could "release and send to Saudi Arabia someone they said was so dangerous that he had to be held for years in a military stockade and could not be allowed to consult with a lawyer."

But that's what happens in comic-opera America when they've got a little list.