A decade of war has obscured the importance of “force planning,” a complex, interactive, inter-temporal art intended to ensure that today’s operational and strategic demands are being met while preparing for a future that may resemble the present or differ from it in unexpected ways. The objective of force planning is to create a future force structure of the right size and the right composition (force mix) to achieve the nation’s security goals, in light of the security environment and resource constraints. In essence, the force planner must answer two questions. First, what capabilities do we need to fulfill the requirements of our strategy, in light of the security environment? Second, what is the appropriate size of the force—in other words, how much is enough?

Although former Secretary of Defense Donald Rumsfeld’s Pentagon attempted to both fight today’s wars and “transform” the force at the same time, the emphasis unsurprisingly shifted over time to the latter. Today’s force is not only worn out but also perhaps mismatched to an emerging security environment. Thus, as the wars of the last decade wind down, it is time to return force planning to its central place in overall defense planning.

In theory, force planning is a very logical process that flows from the choice of a strategy. To implement the chosen strategy, the force planner identifies the strategic requirements—the military tasks required by the strategy—that must be fulfilled to implement the strategy and the operational challenges—the obstacles—that must be overcome.  To overcome these operational challenges and fulfill the strategy-driven requirements, military planners develop operational concepts and identify the necessary military capabilities. These operational concepts and required military capabilities help the planner identify the characteristics of the force and drive the acquisition of forces and equipment.  Throughout the process, the planner must constantly evaluate any risk that may be created by a potential ends-means mismatch. 

Today, U.S. force planning is complicated by several factors: uncertainty about the future security environment; the lack of any real strategic guidance on the part of the Obama Administration to address this uncertainty, and the precipitous decline in U.S. defense spending. To paraphrase the Cheshire cat’s comment to Alice, if you don’t know where you’re going, any road will get you there. A clear conception of strategic ends and the challenges thrown up by the security environment is necessary to minimize the adverse impact of declining resources for defense.

The uncertain security environment requires that the United States be prepared to confront a wide range of adversaries across the spectrum of conflict. At one end of the spectrum is the potential threat to U.S. security by the rise of China. Indeed, the similarities between the cases of Wilhelmine Germany and Great Britain at the turn of the twentieth century, and China and the United States today are compelling. At the other end of the spectrum lies what we confronted in Iraq and Afghanistan, an environment in which our opponents rely on asymmetric, low-tech tactics and networks of people rather than networks of state-of-the-art weapon systems

Notwithstanding the failure of the Obama Administration to provide strategic guidance, it is possible for planners to infer what must be done by turning to strategy in general as a guide to force planning. Strategy is designed to secure national interests and to attain the objectives of national policy by the application of force or threat of force. Strategy is dynamic, changing as the factors that influence it change. Potential mismatches between ends and means create risks. If the risks resulting from an ends-means mismatch cannot be managed, ends must be reevaluated and scaled back, means must be increased, or the strategy must be adjusted. Until the advent of the Obama Administration, U.S. presidents took it for granted that the goal of American strategy was to underwrite a liberal world order (free trade, freedom of navigation, liberal governance) by providing the “public good” of global security, while preventing the emergence of a rival seeking to undermine such a liberal world order.

At a minimum, the United States must maintain a force capable of accomplishing certain military tasks: to defend the territory of the United States and its strategic approaches against attack, seizure, or interdiction by protecting against a terrorist attack or missile strike against U.S. territory, and to threaten the sanctuaries of would be attackers, whether state or non-state actors. 

Thus, U.S. forces are required to project and sustain power at great distances from the continental United States, shape the security environment by means of forward presence, reassuring friends and allies and deterring adversaries, and in the event that deterrence fails, defeat an adversary in one or more theaters. The major problem U.S. planners face today is that the proliferation of militarily useful technology means that the operational environment will be far less permissive than it has been in the past.

Operational challenges that U.S. force are likely to face in the future include: confronting a wide range of adversaries in a complex battle-space; the absence of access to forward bases and the resulting “tyranny of distance” that U.S. force must overcome to project power; the likely adoption of asymmetrical anti-access strategies (area denial/ anti-access, or AD/A2) by potential adversaries resulting from the proliferation of militarily useful technology; maintaining our own information security while degrading that of an adversary; dealing with the effects of weapons of mass destruction/effects and the necessity of contending with mass population problems such as operations in urban terrain, refugees, and epidemics.

To overcome these operational challenges, U.S. planners need to develop operational concepts and military capabilities that will permit the United States to achieve its goals. For instance, to overcome the tyranny of distance and project power against an adversary’s sanctuary in the face of AD/A2 threats, the United States must be able to dominate the world’s commons, especially sea, space, and cyberspace and prevail in the world’s contested littorals. The U.S. military must be able to execute operations at intercontinental distances, conduct long-range precision strikes while protecting its forces against ballistic and cruise missile attack; continue to exploit stealth technology in order to perform operations based on stealthy, extended-range, unmanned system-dominated air warfare; and carry out distributed, deep-strike, non-linear ground operations, as well as submersible, distributed, sea-based power projection—both strike and amphibious. But flexibility is critical. As the American experience in Iraq and Afghanistan illustrated, the United States does not always get to choose the area of military competition.