Of the twenty-one years that have passed since the United States invaded Panama to remove the military dictator Manuel Antonio Noriega, the US has been at war for fourteen. In the Balkans, Iraq, Afghanistan, Iraq again, and now Afghanistan again, we have fought and are still fighting essentially land campaigns that, in addition to having indecisive outcomes, have transformed our idea of military deployment from the traditional balance of sea and land strengths that sustained American foreign policy in the twentieth century to a mixture of counterinsurgency efforts (which include training others in counterinsurgency), constabulary operations, and nation building. These ground-based operations reflect and reinforce the United States' unarticulated drift toward a national security strategy that sometimes looks like a grand Whac-A-Mole game. US military attention, for example, is at present most alert and concerned about the possibility that Yemen and nations in the nearby Horn of Africa will be added to the list of disintegrating states that al-Qaeda and other groups can use as bases for terror. These too will become candidates for interjecting American land forces.

The political arguments against such uses of American force are well enough known: we have become the world's policeman; democracy cannot or should not be built by force; the regimes we support are unworthy of the sacrifice our military is asked to make; and so on. But the shift in the United States' grand strategy that has heretofore reflected our geographic position and natural strength as a maritime power is an issue of a different intellectual order. In the past we used sea power to keep distant conflict from approaching American shores, and projected our influence through alliances with states that surrounded potential threats. This strategy has been gradually replaced, however, so that the US now seeks the appearance of alliances but ultimately supplies the preponderance of boots on the ground itself. The shift is a profound departure from the once unified strategic vision that guided America for more than two hundred years.

Grand strategy is the set of objectives that unite a nation's foreign and military policies at any single moment and give a coherent view over a long period of time of how a state protects itself and its interests. Since it became a major world power early in the twentieth century, the United States has been guided by Britain's centuries-old maritime grand strategy. British policy used naval power to secure the sea-lanes on which its trade and eventually its colonial empire depended, to support and reassure its continental allies, and to protect itself from waterborne assault. Complementing its maritime strategy was the long-standing effort to preserve security by building continental alliances and coalitions—contributing ground forces only where necessary—to prevent the emergence of a dominant European power that might eventually challenge Britain at sea.

In the early eighteenth century, the prospect of a single monarch controlling Spain and France offered one such possibility. Britain crafted an alliance with the Dutch, several German principalities, Prussia, and Portugal to prevent the rise of such a continental hegemon capable of upsetting the European balance of power. At the same time, Britain preyed on the sea-lanes used to ferry New World gold back to Spain, and on French possessions in the Caribbean that supported the wars of Louis XIV. Exhausted, the combatants negotiated separate agreements under the Treaty of Utrecht, which averted the effective union of France and Spain.

A century later, when France again sought continental hegemony, this time under Napoleon, English policymakers resisted again, making alliances and coalitions with continental powers that nibbled at, and then destroyed, French power on land. But sea power was key to this land struggle. It maintained Britain's ability to transport troops and conduct commerce and eventually destroyed the French and Spanish combined fleet along with Napoleon's ability to invade England.

America's own grand strategy formed around maritime power, beginning with wars against the Barbary pirates and continuing with the War of 1812 and the riverine and coastal encirclement that helped the Union choke the Confederacy during the Civil War. At the end of the nineteenth century, the war with Spain ended the last of European holdings in the Americas and simultaneously secured US interest in and responsibility for the Philippines. By 1914, the Panama Canal allowed US sea power to move smoothly and strategically between the Atlantic and Pacific, acknowledging America's increasing interest in the great breadth of ocean on each of its coasts. Theodore Roosevelt's construction and around-the-world deployment of a large US battle fleet underlined the same idea: that the world's oceans provided in-depth strategic defense for America's increasingly global interests.

US policy during World War I rested as much on safe transit of a large number of American troops and a huge amount of logistical support through the Atlantic's U-boat-patrolled seas as it did on a coalition strategy with allied forces on the ground in northern Europe. When conflict broke out again two decades later, the dovetailing relationship between sea and land power remained central to American grand strategy. The United States supplied the tools Winston Churchill asked for, but only after they traveled safely over water first. Field Marshall Bernard Montgomery told an audience nearly a decade and a half after the end of World War II that "the Second World War was fundamentally a struggle for the control of the major oceans and seas—the control of sea communications—and until we had won that struggle we could not proceed with our plans to win the war."

The danger that a single power would control the European continent remained after the Nazis disappeared, when the USSR's power reached the border of divided Germany. Again, US grand strategy aimed to prevent a hostile power from dominating the continent. NATO was a coalition of continental democratic states that stood between the Soviets and the waters surrounding the European peninsula. Our allies could be certain that we would resupply them with secure seaborne supplies and ground troops. At the same time, US naval combatants would whittle down Moscow's submarine-borne strategic reserve and provide diversionary assaults on the flanks of the large Soviet ground force if it struck westward.

For a century, in other words, American grand strategy has, through alliances backed by maritime power, aimed to prevent the rise of dangerous peer competitors on distant continents. Seaborne power has helped maintain coalitions and, through its very presence, deterred nuclear exchanges. Perhaps most important, sea power, through its encompassing, trans-oceanic role, has protected freedom of navigation and occasionally acted to enforce standards of national sovereignty and non-aggression, which serve America's broadest interest in a peaceful global order.

Several major policy changes since the end of the Cold War show that this fundamental idea of grand strategy has shifted. The invasion of Iraq in 2003 and the continuing war in Afghanistan are continental struggles in which no threat of a rising peer competitor exists. Allies were called on and coalitions formed. Naval power is employed in the War on Terror. But US grand strategy has come loose from the moorings, namely, that significant hegemony in either of the world's two most important continents, Europe and Asia, constitutes a perilous threat to American security, and that partnership with the states that separate these threats from the world's major oceans offers the first and surest way to protect America's interest in preventing the approach of danger.

The change in direction of US strategy is more than a political and geographic refocus. America's armed forces are being reinvented to cope with the type of warfare they have experienced in the Middle East. Under the current and previous administrations, the Defense Department has changed itself into a massive counterinsurgency operation. Secretary of Defense Robert Gates's next budget emphasizes "rebalancing the force," an expression of the Pentagon's shift in the direction of counterinsurgency operations, and thus an expansion in America's direct or indirect continental engagement. The budget lists "more robust funding" for helicopters and air crews, special operations personnel and their equipment, increases in electronic warfare capabilities, and the purchase and deployment of more unmanned vehicles. Major conventional weapons systems, such as the Air Force's F-22 fifth generation fighter or the building of a new class of Navy cruisers, have been abbreviated or cancelled entirely.

Promotion policy has paralleled acquisition policy. Two years ago, General David Petraeus was brought back from Iraq to head the board that selects Army officers for promotion from colonel to brigadier general. Nearly half of those selected had been serving or would serve in the Middle Eastern wars, —a clear indication that the Army sees future warfare as an image of today's conflict projected onto a larger and more distant screen. Absent from the Pentagon's calculation about the nation's strategic future are questions about whether Americans will tolerate a chain of small wars to prevent states from failing, deny safe haven to small numbers of terrorists, and increase regional security and promote democracy.

Also virtually absent from strategic calculations is China. The Quadrennial Defense Review published by the current administration early in 2010 mentions China's rise and its large population. Otherwise, the report, which is supposed to survey the nation's defenses and set its future course, remains silent about the possibility of strategic competition with Asia's largest state, whose oft-declared intent is to deny the US access to the western Pacific.

The rise of a dominant power in Asia threatens what should be the major goal of America's security strategy—i.e., promoting a world order that encourages political liberty and expanding commerce based on free enterprise and such international norms as respect for sovereignty and untroubled transit through international waters—at least as much as the contest for European or Eurasian hegemony once did. China's mercantilist economy based on exports and sustained by the manipulation of currency (which also bolsters unproductive state-owned industries); its recent bullying of smaller neighbors over sovereignty questions in the surrounding seas; its growing nationalism; its increasingly powerful navy—all of these factors demonstrate Beijing's steely ambition to become the Asian hegemon.

If China should achieve these objectives, the consequences for America would be profound. The network of US alliances—with democratic Asian states like Japan, the Republic of Korea, and whatever remains of Taiwan after it is inevitably attacked—would splinter as these and other smaller Asian states seek economic, diplomatic, and military accommodation with China. Denied access to the region, the US would lose its century-old status as a major Pacific power, not to mention the bases from which it can now project military force (both aerial and amphibious) as well as support naval operations throughout the region. China's authoritarian economic and political systems would become the model of governance and regional intercourse. Chinese influence underwritten by its unopposed naval power would reach far; a diminished US Navy would find itself impotent in shielding India. With Asia's huge population—about half the world's people—and growing wealth, America's loss of status as the major Pacific power would spell its demise as a great international force.

Jihadism in Afghanistan or Yemen—or any of the other places to which it will surely migrate from wherever it may be temporarily defeated—offers no such prospect for American decline. Nonetheless, the costs of combat operations in the Middle East now reach close to one-third of the entire annual defense budget, and Congressional Budget Office predictions of American sea power show a significant decline in the future size of the US combat fleet. As other conventional forces dedicated to the western Pacific are increasingly supplanted by the Defense Department's emphasis on counterinsurgency, our traditional, effective, and balanced grand strategy is at precisely the same serious risk as our staying power in Asia.

The US should exit large-scale engagement in Afghanistan as soon and as honorably as possible. The surrounding Central Asian, Turkic-speaking states have at least as large an interest as the US does in preventing Islamists from returning to power in Kabul. Assistance to those states, selective employment of US special operations forces, and strikes from unmanned aerial vehicles (UAVs) may not utterly destroy the Taliban—but current US policy is not headed in this direction either. And the cost in blood, money, and strategic focus are minimal compared to the opportunity costs (in Asia and the Pacific) of America's concentration on an expensive war in Afghanistan that fails the first test of successful counterinsurgency strategy: the ability to control the defended state's borders. In NATO's gradual loss of heart, US policy also lacks the minimal demands of a coalition strategy: dedicated allies who share the brunt of the fighting. The current course promises only mounting expense and increasing domestic political alienation, the predictable consequence of which will be the general weakening of America's defense effort, which in turn will only degrade our ability to face challenges in Asia.

Setting US grand strategy back on course will be difficult for a host of domestic reasons. Republicans still bask in the warm glow of success for having steadfastly opposed the Soviets and supported military action generally since the 1960s. Republicans are the party of strength and want to continue to be seen this way.  Pulling out of Afghanistan and forgoing other large assaults on the jihadists risks being interpreted by the electorate as weak, and advocating such a course could open deep divisions within the Republican Party. Democrats would have their own problems to contend with, stemming from decades of opposition to the use of force and major weapons systems, which has contributed to low public support for their foreign and national security policies. Even as recently as the 2008 election, President Obama was forced to avoid the appearance of weakness on foreign policy by balancing his opposition to the Iraq War with support for the one in Afghanistan.

In other words, neither Republicans nor Democrats are likely to see votes in a reconfiguration of our grand strategy. But failure to consider these large questions only enables our drift toward seeing failed states and jihadists as major threats that demand the use of American ground forces and counterinsurgency doctrine, tactics, and equipment. What is needed here is that which has eluded the United States for the last decade, since China's rise and the threat of terrorism both became starkly obvious: a public debate over future threats to our security and how best to meet them. What is our foreign policy and how will grand strategy advance it?

The problems of a decreasing US fleet should be at the heart of this discussion. Chairman of the Joint Chiefs Mike Mullen said in June 2010 that "our national debt is our biggest security threat." One of the most likely sources of reducing the debt is defense spending. Our fleet today is less than half the size it was during the Reagan administration. Further cuts will clearly decrease American sea power, which is ultimately far more expensive to replace than to sustain. Such a loss also takes decades to overcome, time that would permit an opponent like China to solidify. The size of the US fleet should be increased to 350 ships within the next decade (from about 285 now), and American political leadership, if it is unwilling publicly to argue for this naval program as critical to maintaining our status as a great Pacific power, should allow the Navy to offer such a justification in its arguments before Congress.

To prevent bureaucratic strife, the defense budget has for years been divided equally. This was not always the rule. As American grand strategy once made deliberate choices, the division of the defense budget once reflected them. In 1958, when the Eisenhower administration placed its hopes for strategic deterrence primarily in the Strategic Air Command, the Air Force received 48 percent of the budget. The Navy's portion was almost 29 percent, and the Army received 21 percent, down by nearly a half from its 39 percent share during the Korean War.

After Washington ends our large-scale commitment to wars in the Middle East, it must commit a division of the defense budget toward maintaining the current balance of power in Asia and the western Pacific region. This should of course include a stabilizing US presence carried out by the military services best situated to the task. If "strategy" has any meaning, it must choose among competing claims and place informed bets. Is the contentment of our three military services a greater good than an allocation of resources that sustains our power in Asia and prevents the continued rise of a rival regional hegemon? If the US cannot make such strategic decisions under the burden of increasingly straitened national resources, are we still capable of maintaining international leadership, much less our own security?

Better division of resources and cuts in the bloated network of centrally run defense agencies can also help fund strategic restructuring. The Defense Logistics Agency, for example, which purchases food, fuel, medical supplies, and a host of other items from spare parts to uniforms, employs 26,000 people, or 3,000 more than the number staffing the Pentagon. The Defense Contract Audit Agency operates more than 300 field offices with 4,000 employees. The Defense Finance and Accounting Service, which mails paychecks and travel reimbursements, employs 12,000 people. Another 10,000 work at the Defense Contract Management Agency. The Defense Commissary Agency, which sells groceries and household supplies to the military, has 6,000 employees. Taken together, that's 58,000 employees, or more than one-fourth the size of the Marine Corps.

Effective strategic restructuring also requires more attention to alliance management. China is surrounded by states that, like the US, wish to avoid another cold war and hope for a neighbor that projects influence by economic interests rather than by fear. Recent incidents like the collision between Chinese and Japanese vessels near the Senkaku Islands (and the diplomatic wrangling that followed), China's suspension of rare earth sales to Japan, Beijing's declaration that the international waters of the South China Sea are a core national interest, China's seizure of nine Vietnamese fishermen near the disputed Paracel Islands, and China's first-ever live-fire military exercises in Tibet near the Indian border—all of these, which occurred within the last six months, preview what Asia will look like if China establishes hegemony.

Hillary Clinton and Robert Gates have both used visits to Hanoi as platforms to remark that resolving these disputes between China and its neighbors is an American interest. They're right to do so. But they also need to understand that Beijing's ability to resolve the many regional territorial disputes in its own favor depends importantly on superior naval and amphibious power. This power, supported by land-based naval aviation and anti-ship ballistic missiles, also threatens US bases in the western Pacific and US naval presence throughout the region, especially if our fleet continues to diminish. Diverting China from its naval ambitions would reassure the region and show China's rulers that command of the seas will not come automatically from investing in a large navy. Strengthening ties between India and the US advances this goal. So would closer association with the Uighur Muslims in China's Xinjiang Province, whose dissatisfaction with the local Han Chinese population occupied Beijing's attention in the summer of 2009. The mutually suspicious relations between Russia and China offer another opportunity to divert China away from its oceanic east. The US is seen in the Pacific as an advocate of balance, stability, respect for sovereignty, freedom of navigation, and security. China's recent actions, however, have reinforced the views of its neighbors that instead the US stands for the exact opposite. Our policy should exploit this difference in regional perceptions to the fullest.

American maritime power and presence play to our strength—the sparing and selective use of force that resolves or prevents crises, demonstrates resolve, and supports allies united by the shared objective of avoiding conflict by assuring a balance of power. The same cannot be said for the detour we have taken into land conflicts in Afghanistan. A return to our most basic strategic principles requires a recalibration of how to allocate the defense budget, a radical change in managing our defense assets, more assertive alliance management, the recognition of China's growing naval reach as a serious threat, and the reinvigoration of our maritime strength. This will not only secure peace in Asia. It will preserve America's status as the world's indispensable power.