The Esquire article quotes Admiral Fallon as urging a “combination of strength and willingness to engage.”

Readers of the Esquire article who are among the admiral’s boosters said they did not believe on reading that piece that Admiral Fallon himself had made comments that could be viewed as insubordinate to the president.

But the cast of the lengthy piece put the admiral at odds with the White House.

“If, in the dying light of the Bush administration, we go to war with Iran, it’ll all come down to one man,” the article begins. “If we do not go to war with Iran, it’ll come down to the same man.”

Both Mr. Gates and Admiral Mike Mullen, chairman of the Joint Chiefs, have maintained an unwavering public line that disagreements with Iran should be resolved diplomatically, and that any military option remained only the last resort.

“I think that the secretary has made clear and I think Admiral Fallon has made clear that the first priority of this administration is to deal with our problems with Iran in a diplomatic fashion,” Mr. Morrell said Monday. “That is our first hope. That is our first effort. However, we have all made clear, time and time again, that nothing, no avenue is off the table.”

Democrats pounced on the retirement announcement, with Senator Harry Reid of Nevada, the majority leader, calling it “yet another example that independence and the frank, open airing of experts’ views are not welcomes in this administration.”

Senator Carl Levin of Michigan, the chairman of the Armed Services Committee, said he was sorry to see the admiral go. “Admiral Fallon is well known for his excellent diplomatic skills in representing the United States overseas,” Mr. Levin said. “I can only hope that the decision to retire was his own.” And Senator Russ Feingold of Wisconsin, who often differs with the administration on foreign-policy issues, said that “the credibility which Admiral Fallon brought to the issues he was involved in will be sorely missed.”