How many soldiers do we really need?

How many soldiers do we really need?

How many soldiers do we really need?

Military analysis.
June 23 2004 5:11 PM

The Pentagon's Fuzzy Math

Does anyone know how many soldiers we really need?

The occupation has forced the Pentagon into ever more elaborate, Rube Goldberg-like arrangements to maintain troop strength in Iraq. It has issued "stop-loss" orders preventing soldiers from retiring when they're supposed to. It has called up members of the Individual Ready Reserve who've completed their active service obligations. The next Iraq rotation is slated to include "opposing force" units from the Army's premier training centers in California and Louisiana—a move some have likened to eating the Army's seed corn because these units play a key role in training the rest of the force to fight—as well as tens of thousands of reservists, because the active-duty force has been all but tapped. The situation has gotten bad enough that both houses of Congress have sped through bills to permanently boost the size of the 482,000-man Army and 175,000-man Marine Corps.

But adding more troops for their own sake may not be the right answer, despite the current strains on the military from the Iraq and Afghanistan missions. So far, no one is asking the most fundamental question of all: How many troops does the United States really need? Those who want to make the Army bigger assume that adding more troops will magically solve the military's overstretch problems, but that's not necessarily the case. Without an honest assessment of U.S. military requirements, we have no way of knowing how many troops to add (and what kind) or whether drastic measures (like a draft) might be necessary. More important, an honest study of U.S. military requirements may tell us that added manpower is not the answer and that other solutions will buy more bang for our taxpayer buck.


Calculating optimum troop strength is not a new problem, but it has become a lot harder in the past 15 years. During the Cold War, U.S. planners could look at Warsaw Pact strength, do some fuzzy math to adjust for technology and skill differentials, and predict how many troops the United States needed to block a Soviet march through West Germany's Fulda Gap. Erroneous assumptions and interservice rivalries sometimes corrupted the process. (In one famous example from the late 1970s, a set of Navy war games consistently projected that the Navy needed 13 aircraft carrier battle groups—regardless of the scenario that was played.) But despite those flaws, the process had fidelity because we could accurately calculate the Soviet threat and measure our forces in comparison to theirs.

But now the military has to prepare for myriad threats, from aggressive states like Saddam's Iraq to failed states like Somalia to non-state terrorist groups like al-Qaida. In the early 1990s, the Pentagon developed the "2 Major Regional Conflict" doctrine, which held that the United States should be capable of fighting two major regional wars at once. Elaborate war games were conducted to figure out how many forces would be necessary to meet this paradigm, and the results drove subsequent requests for personnel, equipment, and force structure. The 2MRC model quickly proved insufficient for real life. In the '90s, smaller deployments to Somalia, Haiti, Bosnia, and Kosovo stripped the Army's capability to fight two wars at once. These deployments also highlighted the disconnect between the wars the Army planned to fight and those missions it was actually given.

On June 21, 2001, Defense Secretary Donald Rumsfeld presciently told the Senate Armed Services Committee that this two-war construct needed to be reexamined. He was right then, and he's even more right now after the cataclysmic events of Sept. 11 and the wars in Afghanistan and Iraq. Yet despite the obvious need for change, the Pentagon maintains a doctrine only incrementally different from the old 2MRC model. Today's National Military Strategy is a "1-4-2-1" model, meaning:

1) Defend the United States;
4) Maintain forces capable of deterring aggression and coercion in four critical regions: Europe, Northeast Asia, Southwest Asia, the Middle East;
2) Maintain a capability to combat aggression in two of these regions simultaneously;
1) Maintain a capability to "win decisively"—up to and including forcing regime change and occupation—in one of those two conflicts "at a time and place of our choosing."

But this model is failing spectacularly when it comes to dealing with the reality of Iraq. The 1-4-2-1 paradigm effectively commits us to holding everywhere else in the world for as long as it takes to extricate U.S. forces from Iraq. If the North Koreans attack South Korea, or more likely, if North Korea implodes, the United States will be hard-pressed to dispatch ground troops to help, although we still have a formidable air and naval response capability not tied down in Iraq.

The 1-4-2-1 model also provides very little help in predicting a force size because the range of possible post-9/11 missions is so vast—everything from formal major regional conflicts to small special forces and civil affairs deployments (as in the Philippines) to ongoing peacekeeping (as in the Balkans) to special ops works all over the world. The 1-4-2-1 model still sees military requirements through the prism of state-based warfare. But as the post-9/11 deployments show, that prism may be anachronistic. Tomorrow's major military deployment might not be for combat at all—it might require the deployment of an expeditionary nation-building force to stave off a humanitarian crisis. A new military planning model ought to take these kinds of missions into account, too.

In many of these places, firepower might not be the answer, and the 1-4-2-1 model also fails to predict the other kinds of forces which might be necessary for a given situation. If America decides to intervene somewhere like Sudan, it will need a mix of civil affairs troops, military police, engineers, and medical personnel, not just pure combat forces. Furthermore, military forces alone may not be sufficient; we may need to create units with the Treasury Department capable of managing the economic aspects of nation-building, or within the Department of Justice to manage the legal parts of the job. The 1-4-2-1 model also assumes the mission will end when major combat operations end—something which has proved to be wildly off the mark.

Finally, the 1-4-2-1 model is opaque. War planners may know how this model gets translated into personnel requirements, but congressional staffs and the public do not. Thus, politicians have a tendency to throw out arbitrary numbers, like the 20,000- and 30,000-man troop increases now being weighed on Capitol Hill without having any precise idea of what the Army really needs.