Coming from Robert Gates—the epitome of the soft-spoken, buttoned-down public servant—the rebuke was particularly striking. Military officers, Gates said last week, should give their advice to America's civilian leadership "candidly but privately," an allusion to Gen. Stanley McChrystal's remarks in London about the need for counterinsurgency, not counterterror, in Afghanistan. Less noted was the fact that Gates included civilians in his admonition, a broader criticism of all leaks. But the general's comments, which came in a question-and-answer session after a speech to the International Institute for Strategic Studies, are the ones that have roiled Washington and the foreign-policy establishment, producing a head-snapping conversation in which conservatives are cheering the suggestion of dissent within the ranks and liberals are going on about how military officers should shut up and salute. Consistency, though, has never been an especially widespread partisan virtue.

The McChrystal incident raises an interesting question: if commanders cannot speak their minds in such a forum—and the general was the very model of reason and grace—then what are the rules for commanders to engage in public debate? Many liberals have suddenly discovered Article II of the Constitution, arguing that civilian control of the military means soldiers should not express their views outside the chain of command. There is much to be said—in some senses, everything to be said—for officers restricting their comments, but I suspect the left would be taking a very different view of McChrystal's speaking his mind if the general were arguing a position with which it agreed.

In politics and in war, truth can be elusive; often all we can do is muddle through, trying to make the best of things. McChrystal knows better than anyone the complexities of what he faces, and if you read the whole speech he delivered in London you see that he was at pains to make the difficulties at hand as clear as possible.

Think about the implications of the argument that McChrystal has been too candid. If we accept that argument, then if a general appears before Congress or with a president or a secretary of defense to discuss a strategic matter, is he required to say whatever the civilian leadership has told him to say? If so, does that not risk the creation of a public-relations Nuremberg problem in which the military is forced to follow a script, setting the stage for a culture in which officers follow orders blindly? This is an extreme way to put it, but we are, after all, talking about how democracies wage war.

History is not very helpful on this point. Douglas MacArthur is a bad example. He defied a president; McChrystal has not yet even disagreed with one. Still, the cultural imperatives within the armed forces are clear. As our longtime defense correspondent John -Barry notes, the tradition in the American military is captured best in Gen. George C. Marshall's dictum that commanders should present their views in private and then resign if they disagree sufficiently with the decision of the political leadership.

The Marshall doctrine is a good rule of thumb. To restrict ourselves to a one-way conversation controlled by the White House and the civilian leadership of the Pentagon, however, seems less desirable than what we are experiencing now with Afghanistan: a national debate about mission and means in which the military commander has dispassionately expressed his view of the matter. It is easy to see how talkative and opinionated generals could cause no end of trouble, the usual example being a hawkish military opposing a dovish president. So if we are to have a McChrystalized culture of conversation about our options, then the general in question must be calm, deliberative, and nuanced (which McChrystal was). Second, the general must make clear that he will faithfully execute the final decision of the civilian leadership (which McChrystal has). As Marshall noted, there may be cases where the general feels he must resign, but such dire instances might be fewer and farther between if officers feel they are able to say what they think publicly when every other player in the drama, from lawmakers to vice presidents, is being heard.

The issue is complicated, but then most issues of significance are. McChrystal appears to be a good man trying to do a nigh-impossible job. At least the general in whose hands lie the lives of thousands of soldiers and in whose success may lie our own national security chose to be clear now, in real time, when it matters, rather than waiting for a book contract. He has told us what he thinks when it can make a difference, and for that we should be grateful.

© 2009