Tony Snow, the White House press secretary, has brushed off suspicions of an impending U.S. military attack against Iran as just another “urban legend that’s going around.” He may be right, but the legend, which has been churning through the Internet lately, grew out of the threats and hints of President Bush himself and his administration.

Questions as to what further adventures Mr. Bush may be planning go all the way back to his State of the Union Address on Jan. 29, 2002, when he named Iraq, Iran and North Korea as an “axis of evil,” and his doctrine of June 1, 2002, when he asserted the right of pre-emptive war. His unprovoked war against Iraq raised the question of whether or when he would strike Iran and North Korea.

New speculation about an attack on Iran has arisen as the American people and the establishment have largely turned against the war. He needs a new bold move, just as the beleaguered Richard Nixon did when he resorted to his disastrous incursion into Cambodia in the depths of the Vietnam War.

And now have come his seizure of Iranian diplomatic posts in Iraq as suspected links in an aid network for the insurgents, his dispatch of a second carrier group to the Persian Gulf, and his deployment of Patriot antimissile batteries in countries bordering on Iran.

Hints and threats of war are multiplying day by day. Secretary of State Condoleezza Rice described an “evolving” strategy to confront Iran’s “destabilizing behavior.” Vice President Dick Cheney described Iran as a growing threat, “astride the Straits of Hormuz” and its oil-shipping channels and a supporter of Hamas and Hezbollah.

Carrying speculation a step farther, Paul Craig Roberts, an assistant secretary of the treasury in the Reagan administration, who has long been warning of a war against Iran, now argues that the current Bush “surge” is an “orchestrated distraction from the real war plan,” to keep Congress occupied while plans are implemented to widen the war.

How plausible is this urban legend? Only Mr. Bush, Mr. Cheney and a few others know the answer. But their record of secrecy means the public shouldn’t expect an advance announcement, with its risk of popular and congressional revolt. If there is a surprise attack, Iran’s suspected nuclear weapons program could provide after-the-fact justification. Weapons of mass destruction worked once and might be tried again.