In terms of preventing nuclear strikes and special operations against the United States and in terms of managing the geopolitical system in Eurasia, the United States has a tremendous strategic advantage that grows out of its geopolitical position -- U.S. wars, regardless of level, are fought on the territory of other countries. With the crucial exception of Sept. 11, foreign attacks on U.S. soil do not happen. When they do happen, the United States responds by redefining the war into a battle for other homelands.

This spares the American population from the rigors of war while imposing wars on foreign countries. But for the American civilian population to escape war, the U.S. armed forces must be prepared to go to war on a global basis. Herein begins the dilemma. The American strategic goal is to spare the general population from war. This is done by creating a small class of military who must bear the burden. It also is accomplished through a volunteer force -- men and women choose to bear the burden. During extended war, as the experiences of the civilian population and the military population diverge dramatically, the inevitable tendency is for the military to abandon the rigors of war and join the protected majority. In a strategy that tries to impose no cost on civilians while increasing the cost on the military, the inevitable outcome is that growing numbers of the military class will become civilians.

This is the heart of the problem, but it is not all of the problem. The American strategy in Eurasia is to maintain a balance of power. The basic role of the United States is as blocker -- blocking Eurasian powers from adding to their power, and increasing insecurity among major powers so as to curb their ambitions.

Thus, a strategic dilemma for the United States is born. On a grand strategic scale, the United States controls the internation al system -- but at the strategic level, it does not choose the time or place of its own military interventions. Put very simply, the United States controls the global system, but its enemies determine when it goes to war and where, and the nature of these wars tends to put U.S. forces on the tactical defensive.

During the 1990s, for example, the United States was constantly responding to actions by others that passed a threshold, beyond which ignoring the action was impossible. From 1989 onward, the United States intervened in Panama, Kuwait, Somalia, Haiti, Bosnia and Kosovo, not counting lesser interventions in places like Liberia or Colombia. Nor does it count the interventions and deployments throughout the Muslim world and contiguous areas since 2001.

The grand strategic configuration means that the United States does not hold the strategic initiative. The time and place of U.S. intervention is very much in the hands of regional forces. In some cases, th e intervention is the result of miscalculation on the side of regional forces. In other cases, U.S. intervention is shaped by some regional player. For example, Iraq did not expect a U.S. response to its invasion of Kuwait in 1990; Saddam Hussein miscalculated. In the case of Kosovo, a regional actor, Albania, shaped U.S. intervention. In both events, however, given the operating principles of grand strategy, American military involvement is overwhelmingly responsive and therefore, from the U.S. point of view, unpredictable.

Though others determine the general time and place of U.S. intervention, the operational level remains in the hands of the United States. But here too, there are severe constraints. U.S. interventions suffer from a core paradox: The political cycle of an intervention frequently runs in days or weeks, but the time it takes to bring major force to bear is measured in months. That means that the United States must always bring insufficient force to b ear in the relevant time period -- in a kind of holding action -- and contain the situation until sufficient force for a resolution becomes available. Thus, U.S. interventions begin with CIA paramilitaries and U.S. Special Operations Command. At times, these forces can complete the mission. But sometimes, all they can do is prepare the ground and hold until relieved by major force.

Very rapidly, the United States finds itself on the tactical defensive -- lacking decisive force, at a massive demographic disadvantage, and frequently suffering from an intelligence deficit. Even after the main force arrives, the United States can remain in a defensive tactical situation for an extended period. This places U.S. troops in a difficult position.

The entire structure creates another strategic problem. The United States does not control its interventions. It is constantly at risk of being overwhelmed by multiple theaters of operation that outstrip the size of its militar y force or of its logistical base. Between the tactical defensive and the strategic defensive, U.S. forces must scale themselves to events that are beyond their control or prediction.

The unexpected is built into U.S. grand strategy, which dictates that the U.S. armed forces will not know their next mission. U.S. strategy is reflexive. U.S. operational principles do provide an advantage, but that can bleed off at the tactical level. In the end, the U.S. force is, almost by definition, stretched beyond what it can reasonably be expected to do. This situation is hardwired into the U.S. geopolitical system.

The U.S. force was never configured for this reality. It was designed first to cope with a general war with the Soviet Union, focused on central Europe. After the collapse of the Soviets, the technological base remained relatively stable: It remained a combined arms force including armor, carrier battle groups and fighter planes. All of these take a long time to get to the theater, are excellent at destroying conventional forces, and are weak at pacification.

Donald Rumsfeld has identified the problem: The force is too slow to get to the theater in a politically consequential period of time. Getting there too late, it immediately finds itself on the defensive, while the brunt of the early battle focuses on Special Operations forces and air power. The problem that Rumsfeld has not effectively addressed is that occupation warfare -- which is what we have seen in Iraq for the past few years -- requires a multi-level approach, ranging from special operations to very large occupation forces.

Put this differently: The U.S. invasion of Iraq required everything from an armored thrust to strategic bombing to special operations to civil affairs. It required every type of warfare imaginable. That is indeed the reality of American strategy. Not only is the time and place of military intervention unpredictable, but so is the fo rce structure. Any attempt to predict the nature of the next war is doomed to fail. The United States does not control the time or place of the next war; it has no idea what that war will look like or where it will be.

The United States has always built its force around expectations of both where the next war would be fought and how it would be fought. From "Air-Land Battle" to "Military operations other than war," U.S. military doctrine has always been marked by two things: Military planners were always certain they had a handle on what the next war would be like, and they were always dead wrong.

The military structure that was squeezed out of the Cold War force after 1989 assumed that wars would be infrequent, that they would be short, that they would be manageable. Building on these assumptions, U.S. military planners loaded key capabilities into reserve and National Guard units, cut back on forces that didn't fit into this paradigm and then -- even when re ality showed they were wrong -- they tried to compensate with technology rather than with restructuring the force.

Wars have been more frequent since the fall of the Soviet Union than they were before. They occur in less predictable places. They tend not to be brief, but to be of long duration and to pile up on each other -- and they frequently are unmanageable for an extended period of time. The United States does not have tactical advantages with the forces provided.

As a result, the force is deployed far more than planned, troops are forced to rotate too rapidly through assignments in combat zones, and they operate in environments where operational requirements force them too often into tactically defensive situations. That all of this is managed with a force that is drawn heavily from reserves is simply the icing on the cake. The force does not match the reality.

We began by pointing out the goal is -- and should be -- to protect the American public from war, with volunteers placing themselves between home and war's desolation. This strategic goal, while appropriate, creates a class of warriors and a broader class of indifferent civilians. Given the situation, it will follow that sensible warriors, having done their duty in their own minds, will choose to join the ranks of civilians, while civilians will avoid service.

There has been talk of a draft. That is a bad idea for technical reasons: It takes too long to train a soldier for a draft to solve the problems, and today's soldiers need to be too skilled and motivated for a reluctant civilian to master their craft. Moreover, this is not a force that would benefit from the service of 19-year-olds. Many of the jobs in the military could be done by people in their 40s and 50s, who would bring useful skills into the military. We would support a draft only if it included all ages of men and women who had not previously served. There is no reason that an accountant in civilian life could not provide valuable military service in Afghanistan, maintaining logistics inventory. The United States does not need to draft children.

Since that isn't going to happen, and since the United States does not have the option of abandoning its strategy, the United States must reshape the force to meet the single most important reality: The United States will be at war a lot of the time, and no one really knows where or when it will go to war. The challenges in military retention or inability to meet recruiting goals mean that the United States continues to recruit children, as if this were the 19th century.

Geopolitics, Strategy and Military Recruitment: The American Dilemma