Adm. William Fallon, 63, the first naval officer to head U.S. Central Command, has announced his retirement after less than a year on the job. This has prompted speculation among left-wingers that war with Iran is imminent.

That speculation was fueled by an article by Thomas P.M. Barnett in the current issue of Esquire magazine, which described Adm. Fallon as the last man standing against an attack on Iran:

"Well-placed observers say it will come as no surprise if Fallon is relieved of his command before his time is up next spring, maybe as early as this summer, in favor of a commander the White House believes to be more pliable," Mr. Barnett wrote. "If that were to happen, it may well mean that the president and vice president intend to take military action against Iran before the end of this year and don't want a commander standing in their way."

But it probably doesn't. Defense Secretary Robert Gates and Adm. Michael Mullen, the chairman of the Joint Chiefs of Staff, are also said to be opposed to military action against Iran. Mr. Barnett seems to be, at a minimum, overwrought.

Adm. Fallon seemed to think so. The Esquire article was "poison pen stuff" that was "really disrespectful and ugly," he told Tom Ricks of The Washington Post.

The admiral's difficulties stem less from disagreeing with President Bush's policies than from expressing his disagreements in public.

"Adm. Fallon had rankled senior officials of the Bush administration with outspoken comments on such issues as dealing with Iran and setting the pace of troop reductions from Iraq -- even though his comments were well within the range of views expressed by Mr. Gates," wrote New York Times reporters Thom Shanker and David Stout.

An egregious example is the interview Adm. Fallon gave last fall to al-Jazeera television, which undercut administration efforts to put pressure on Iran. Mr. Barnett quoted copiously from that interview in his Esquire article.

"What Fallon [and Barnett] don't seem to understand is that Fallon's very public assurances that America has no plans to use force against Iran embolden the mullahs to continue developing nuclear weapons and supporting terrorist groups that are killing Americans in Iraq and Afghanistan," wrote Max Boot in the Los Angeles Times.

Unnamed officials to whom they talked described the Esquire article as the "last straw," said Messrs. Shanker and Stout.

"The problem wasn't that Fallon was merely pushing back within the administration against a policy he didn't like," wrote retired Marine Col. Mackubin Owens, now a professor at the Naval War College. "The problem was that a uniformed officer was actively working to undermine that policy after the decision had been made -- and that he was also speaking out against the policy publicly while being charged with executing it."

Sens. John Kerry and Ted Kennedy, both Democrats from Massachusetts, said Adm. Fallon's sudden retirement indicates President Bush is unwilling to listen to his military leaders. "The last thing America needs is an echo chamber of top advisers, especially on all-important questions of war and peace," Sen. Kennedy said.

Somehow I suspect that if there were a President Obama, and a senior military leader publicly criticized his plans for withdrawal from Iraq, Sens. Kennedy and Kerry would be howling for his head.

The real question is: To which of his military leaders should the president listen? Adm. Fallon has denied referring to the U.S. commander in Iraq, Gen. David Petraeus, with a string of expletives, but there is no question relations between them were strained.

"He fought Petraeus every step of the way, creating unrealistic demands and extra work," the Los Angeles Times quoted a former senior Pentagon official as saying.

Gen. Petraeus was right about Iraq. Adm. Fallon was wrong. If one of them had to go, the choice is clear.

Michael Ledeen of the American Enterprise Institute thinks Adm. Fallon fell from grace for reasons less lofty than a policy dispute:

"I think it's fair to say Adm. Fallon was an object of scorn and sometimes contempt by a significant number of his immediate subordinates," Mr. Ledeen said. "It had nothing to do with Iran, or for that matter Iraq. Rather it had to do with the man himself, his perceived competence, with the way he dealt with his underlings."