General Stanley McChrystal's abrupt departure from command in Afghanistan precipitated a great deal of commentary about his leadership, about President Barack Obama's decisions, about the challenges now facing General David Petraeus and -- not to be forgotten -- about the wisdom of letting loose in the presence of a freelancer on assignment to Rolling Stone. But the most important debate raised by McChrystal's ouster is that of the counterinsurgency concept he championed. Many have taken this moment to criticize the "cult of counterinsurgency" for misunderstanding the challenges presented by the Afghanistan conflict, and for restricting Western militaries from fighting this war with more violent means, especially airstrikes and indirect fire. And although General Petraeus has indicated few changes to his predecessor's plans, it makes sense to assess the merits of this debate.

Detractors of the counterinsurgency idea cite a conceptual "straitjacket" that inflexibly constrains the military from using violence, and they present the restrictive rules of engagement as an example of counterinsurgency dogmatism and the problems it brings. Many who criticize counterinsurgency offer little constructive suggestions other than to leave Afghanistan or to revamp the doctrine with more leeway for the use of greater force. It is reasonable to suggest that a review of counterinsurgency doctrine may be in order, that this idea may not have been the proximate stabilizer of Iraq, and that the center of gravity in irregular conflicts is not always the people. But the argument that more violence will win the war is just as formulaic and banal. At the other end of the spectrum, others suggest that a lighter touch -- and some deliberate battlefield inactivity -- might help win a few more hearts and minds. Finally, there are those who have resurrected the "counterterrorism-plus" ideas advocated by Vice President Joe Biden and derided by McChrystal.

These criticisms miss the point that no U.S. or NATO operation in today's Afghanistan can avoid four inescapable facts: the problem of international terrorism is a Western problem as much as it is an American problem; the U.S. needs to be in Afghanistan to stop international terrorists from preparing attacks against the West; to be there we must retain the support of the internationally recognized Afghan national government; and to retain the government's support and stop the terrorists the U.S. cannot violate the people of Afghanistan.No matter the official strategy, these facts -- and frustration over assessments of stagnation in Afghanistan -- are the real sources of criticisms of counterinsurgency. Any alternative to counterinsurgency would have to contend with these same facts as well as the criticisms they inevitably precipitate.

A coalition war. The first fact means that the U.S. has many allies in the war that began on 9/11, and NATO's very first invocation of Article 5 was as much a statement of European self-defense as it was a statement of solidarity with the United States. These allies are very important in both sharing the burden and sustaining the international legitimacy of the war, but they also cannot be denied the right to defend themselves against the same threats we face in the United States. Indeed, recent experience reaffirms that Europe confronts similar (and perhaps more serious) problems that we do. This also means that the war in Afghanistan is a coalition war in the modern sense. The political, diplomatic, and military intricacies of fighting this kind of war are as byzantine as the election of a high school homecoming court. U.S. generals who lead ISAF, the International Security Assistance Force, have to develop guidance that is generally acceptable not only to the American public, but also to the politicians, diplomats, generals, and electorates of troop contributing allies. Directives written partly with the maintenance of a coalition in mind will inevitably draw domestic criticisms of being complicated, diluted, or wrong-headed.

A war of necessity. The second fact means that withdrawal or inaction -- however masterful it may be -- are not reasonable options. Packing up and going home leaves Afghanistan to international terrorists who will inevitably use the territory to plan and train for attacks on the West. Worse, adopting a tactically passive stance would cede the initiative and dangerously squander perceptions of Western prestige, thereby emboldening al-Qaeda and its allies. Although building an all-encompassing security regime, a fully functioning democracy, or a prosperous free market system might be helpful to the cessation of international terrorism originating in Afghanistan, these are not necessary if what we need to achieve is the defeat of international terrorists (and their sponsors) targeting Western societies. But the continued involvement of U.S. armed forces is necessary to suppress the attacks of al-Qaeda and its allies.

A war fought as guests. The third fact reminds us that this war is difficult because it is fought with the authority of an internationally recognized, democratically elected government -- Afghanistan. Unlike wars fought against a foreign government in which the broad application of violence against a society is typically legitimized by its official defiance, wars fought on behalf of a foreign government on its soil against non-state actors rarely permit the same level of violence. The irony of the U.S. invasion of Afghanistan is that although the U.S. invaded to depose the Taliban, the American military became a guest of the Karzai government as soon as the Afghan leader attained international acceptance. Some critics suggest that violence may be sufficient to retain the freedom to operate in Afghanistan. However, a request from Kabul to leave would be very difficult to contradict with a gun, for the U.S. would effectively be violating the sovereignty of a government we helped install. Perhaps this is what is meant by the adage, "You break it, you buy it." The difficulties of fighting as guests manifest themselves in the directives of generals who need to retain the trust and confidence of a host nation government.

A war of restraint. The fourth fact means that protecting the people is much more than a tenet of counterinsurgency dogma, it is an inviolable pre-condition that facilitates our continued access to Afghanistan's territory, no matter the concept of our operations. True, doing no harm (or as little harm as possible) to civilians is an unavoidable and indisputable -- if occasionally inconvenient -- aspect of the conflict in Afghanistan, not to mention a norm worth upholding regardless. The suggestion that more liberal rules of engagement might lead to success is problematic because it implies that civilian casualties abroad should somehow become more tolerable to the U.S., its allies, and to the people of Afghanistan. Although there is a moral argument here, the practical and political reasons for protecting civilians in Afghanistan are also significant. Too many civilian casualties will drive non-combatants to support our opponents and jeopardize the relationship with the host government as described above. Even if the strategy were one of all-out pacification by force, civilian casualties would still be a central problem and source of criticism.

This is not an argument for the COINdistas. These facts hold true no matter what idea is implemented, counterinsurgency and counterterrorism-plus included, making this debate a bogus one. There are other knowledgeable people with similar opinions. Critics of the current concept rarely offer a cogent alternative (Austin Long being an important exception) and instead seem to snipe out of frustration or a desire to hedge. Coping with these realities creatively, directly, and effectively is now General Petraeus's challenge.

Alec Barker is a national security analyst and consultant based in Washington, D.C. He is solely responsible for the content of this piece.