The non-war portion of the 2011 U.S. defense budget will be roughly $550 billion. That is more, in constant dollars, than we Americans spent on defense at the height of the Reagan buildup, in the midst of the Cold War. How could this be?

The primary cause is the plethora of missions given to the U.S. military. These days, policymakers want the U.S. military to:

• contain China,
• transform failed states into stable democracies,
• chase terrorists,
• train various foreign militaries to chase terrorists,
• protect sea lanes,
• keep oil cheap,
• democratize the Middle East,
• protect European, Asian and Middle Eastern states from aggression,
• spread goodwill through humanitarian missions,
• respond to natural disasters at home and abroad,
• secure cyberspace, and much more.

The military forces and budget needed to pursue these goals can never be enough. Defining the requirements of our defense so broadly is not just destructive of U.S. national wealth – but is also counterproductive.

Our global military activism drags us into others’ conflicts, provokes animosity and encourages weapons proliferation. We can save great sums and improve national security by narrowing our goals and adopting a defense budget worthy of its name.

A more modest strategy – let’s call it a U.S. doctrine of military restraint – starts with the observation that power tempts the United States to meddle in foreign troubles that we should avoid. George Washington set us on the right track in 1796 when he advised Americans “to steer clear of permanent alliances with any portion of the foreign world.”

Such restraint means fighting the temptation to occupy failing states and to extend indefinite commitments to defend healthy ones.

It would husband American power – rather than dissipate it by spreading promises and forces hither and yon. Adopting this strategy would allow us to safely spend far less – at least $1.22 trillion less over the next ten years, we estimate.

Consider some of the leading arguments for why we spend more on our military today than at any time during the Cold War. We argue that all are flawed.

Contrary to conventional wisdom, counterterrorism does not require much military spending. Large military formations and heavy equipment are most useful in defeating well-armed enemies. Terrorists are mostly hidden and lightly armed. The difficulty is finding them, not killing or capturing them once they are found.

The best weapons in that fight are intelligence and policing. Thus, the most useful military tools today are relatively inexpensive niche capabilities: surveillance and intercept technologies, special operations forces and drones.

Some contend that we can be safe from al Qaeda and other terrorist groups only by occupying and transforming the failed states where they operate. The claim does not bear scrutiny. Few failed states have provided havens to anti-American terrorists.

Even in Afghanistan during the 1990s, the supposed leading example of this phenomenon, the trouble was that the government allied with al Qaeda – not that there was no government.

And we have lately learned that we lack the power and wisdom to reorder unruly states with military occupations, despite great expenditures of blood and treasure. Experience tells us, in fact, that occupations tend to cause terrorism aimed at the occupier – rather than prevent it.

The massive U.S. military budget also cannot be justified by threats from rival nation states. North Korea, Iran and Syria collectively spend roughly one-sixtieth of what we Americans spend on our military. With the possible exception of North Korean missiles, they lack the capability to attack the United States.

They are deterred from doing so in any case. They are local troublemakers – and, as a result, they have local enemies that can contain them.

As for our potential great power rivals – Russia and China – we would have no good reason to fight a war with either in the foreseeable future if we did not guarantee the security of their neighbors. Both lag far behind us in military capability. That would remain the case even with the budget reductions that we propose.

As it stands today, the United States spends about five times more on defense than these two states collectively. As a matter of fact, we account for nearly 50% of all military spending in the world, and the United States’ allies and friends account for much of the rest.

Another argument for high military spending is that U.S. military primacy underlies global stability. According to this theory, our forces and alliance commitments dampen conflict between potential rivals, preventing them from fighting wars that would disrupt trade.

This logic liberates defense planning from old-fashioned considerations like enemies and the balance of power. It sees the requirements of global policing as the basis for the size of the U.S. military. That is no standard at all, which is why hawks embrace it. Boundless objectives justify limitless costs.

That argument overestimates both the American military’s contribution to international stability and the danger that instability abroad poses to Americans. U.S. force deployments in Europe and Asia now contribute little to peace, at best making already low odds of war among states slightly lower. Inertia, rather than our security requirements, explains the perseverance of U.S. military alliances.

During the Cold War, Japan, Western Europe and South Korea grew wealthy enough to defend themselves. We should let them do so. These alliances heighten our force requirements and threaten to drag us into wars, while providing no obvious benefit. Without our forces there, our allies would pay the cost of balancing local adversaries.

There is also scant evidence for the claim that international commerce requires American military protection. The physical threats to global trade today are quite limited. The percentage of shipments protected by military means, let alone U.S. naval vessels, is tiny. And even when political instability does disrupt trade, it has only a minimal economic impact here in the United States.

Hawks also claim that we must spend heavily on defense today to prepare for the eventuality of new rivals. But the best hedge against an uncertain future is a prosperous and innovative economy supporting a capable military that can be expanded to meet rivals should they arise.

We should not greatly cut military spending without thorough-going strategic change. There are efficiencies to be had in our military budget, but making large cuts without reducing commitments would merely impose additional burdens on service-members and their families. Nor should we embrace strategic restraint simply for budgetary reasons.

It is a security strategy first that offers the opportunity to save. Indeed, these recommendations would make sense even without large federal budget deficits. But large deficits make them more pressing and more likely to attract support.

These proposals may seem radical inside the Beltway. But what is truly radical is the ambition that now justifies the size of the U.S. military: The idea that the United States should use its military to secure rich states in perpetuity, arrest disorder in several poor ones simultaneously, insure global stability and spend the better part of a trillion dollars a year to those ends.

Were the United States to truly revive its historical non-interventionist ideals, deeper savings could be had, without sacrificing security.