In my view, George W. Bush has been unduly tolerant of the efforts of civilian career professionals to undercut his policies. But Fallon's abrupt resignation suggests that he and-or Gates decided that things had gone too far when a commanding military officer was lionized for opposing the president's policies in the pages of Esquire.

One of the firmest principles of American public life, established with great deliberateness by George Washington, is civilian control of the military. The vast majority of American military officers over our history have honored and cherished that principle. Fallon, as portrayed by Barnett, seemed to relish brushing it aside.

My guess is that Gates, who was a career professional and whose memoir stresses the continuity of U.S. government policy in different administrations, decided that enough was enough.

Tough questions remain about how civilian commanders should choose and interact with military professionals. Bush's record, in my view, has been far from ideal. He has seemed content with letting others choose military commanders and then accepting their advice with little of the abrasive interaction recommended by Eliot Cohen in his 2002 book "Supreme Command." Only after the debacle of the 2006 elections did he call on David Petraeus.

One wonders how much he pondered the installation at Central Command of Petraeus' critic Fallon. It is surely a difficult thing for civilian presidents to choose able and apt military commanders -- looking back in our history Franklin Roosevelt seems to have been the only commander in chief who had a consistent record of doing so early on. But at least Bush -- and Gates -- have rectified what they must now consider a mistake. And they have reaffirmed the ancient principle of civilian control.