The case for scaling back is strong. Let’s consider the major concerns: Saddam Hussein is gone, and whatever threat Iraqis may one day pose to themselves and the region, they are unlikely to invade anyone. Farther from home, North Korea has acquired nuclear capabilities, but its conventional forces have weakened, and South Korea’s army is greatly strengthened. Russia remains problematic on multiple issues but not because of its military menace to NATO territory. Threats from Iran or China, at least in the short term, are much more likely to involve U.S. naval, air and special forces (which should retain a capacity for handling more than one major operation at a time). The uncertainty and instability from Syria to Yemen to South Asia, however potentially worrisome for American interests, are unlikely to again require large-scale U.S.-led action.
All that said, budget hawks should beware of pushing this argument too far. The one-war paradigm is not a prescription for cutting the Army and Marine Corps by a third or more. Cuts in force structure and personnel should not exceed 15 to 20 percent, relative to current levels, and could be made only gradually, after the Afghanistan campaign winds down. Ten-year savings would reach perhaps $150 billion. That is much of the roughly $400 billion mandated by the August provisions of the Budget Control Act but hardly a dent in the (ill-advised) nearly trillion-dollar target required by sequestration.
To carry out this approach responsibly, the United States would still need an active-duty Army and Marine Corps almost as large as those of the Clinton years. Then, we thought we had a two-war capability, a fallacy underscored by events in Iraq and Afghanistan. Within a one-war paradigm, we could no longer rely on the force package intended for a second war to compensate for any underestimations made in planning for a first war. Nor could we rely primarily on the National Guard, as rapid response would be even more critical to addressing problems before they could metastasize.
The United States would still need capabilities for possibly simultaneous additional missions, which would probably be smaller in scale than full-fledged war but could be long in duration. Rather than a two-war paradigm, we would want a “1+2” framework for sizing ground forces — the “1” referring to a substantial regional war; the “2” being smaller, multinational but potentially long-lasting contingencies such as a stabilization effort in Afghanistan (or Syria or Yemen).
Some critics will argue that capacity for even one war is too much, that the nation is tired and broke, that counterinsurgency is passe and ground combat obsolete. We convinced ourselves of a similar argument about counterinsurgency after Vietnam, only to be unready for Iraq and Afghanistan a quarter-century later. No new ground wars may be likely, but we must be ready for the unlikely. If, say, tensions between North and South Korea escalate or the North collapses, leading to large-scale mayhem, U.S. forces would have to move fast, along with South Korean units, to stem any bombardment of Seoul and to prevent nuclear materials from leaving the peninsula.
U.S. forces should also retain a capability to remove Iran’s regime. We would consider such an operation only under the most grave circumstances — say, after a direct Iranian attack against the American homeland rivaling Sept. 11 in scale. We would not have enough ground forces to occupy Iran after a march on Tehran, but we should nonetheless have a conventional military counter to possible large-scale terrorism supported by the Iranian state. A robust one-war potential within the nation’s ground forces, plus some capabilities for lesser concurrent missions, is therefore necessary — but also enough for this moment in history.
Critics will also argue that a one-war paradigm could weaken deterrence. We do not want to trigger aggression from those who believe that America is powerless to deal with more than one ground conflict at a time. Part of the answer to this valid concern, shared by Obama and Panetta, is to plan, should we become engaged in a major land war, to promptly activate part of the National Guard and start enlarging the active-duty Army and Marine Corps. The George W. Bush administration took such action belatedly a few years ago, resisting it even after wars in Iraq and Afghanistan were underway; we need not repeat that mistake.
Ultimately, strategy is about minimizing, not eliminating, risk. The threats from maritime contingencies in the Western Pacific and Persian Gulf, and from fiscal weakness, exceed those from simultaneous ground wars. The U.S. defense budget should be adjusted accordingly.