Defense of the American homeland and that of key allies in Europe and Asia are two widely accepted negative objectives. Ensuring that the global commons remains open for trade and communication is another. Limiting the effects of global warming is quickly becoming another vital, negative political aim. Finally, holding China’s military rise and adventurism at bay commands greater and greater importance in American policy circles. In short, conserving a global status quo spells hard, painstaking work.

Three Examples of When and When Not to Triage:

Three examples illustrate the utility of employing this two-step evaluation of national security interests—ranking goals by importance, and by whether they are positive or negative—as a guide for assessing U.S. commitments. The first assesses how U.S. strategy towards China combines pressing political value with converging negative and positive aims. The second entails the negative aim of supporting Iraq in its battle against ISIS. This aim is of moderate political value and cost. And finally, there is the more problematic case of Afghanistan. The value of maintaining the status quo in Afghanistan may no longer merit an indefinite outlay of American resources.

U.S. strategy vis-à-vis China shows how negative aims can converge with positive political interests in Asia. Over the past two decades, China has become the only viable near-peer competitor boasting the potential to threaten U.S. regional hegemony. In response, Washington is pursuing a negative aim to limit China’s influence in East Asia. It has done so by increasing the U.S. Navy’s presence in the area, refurbishing relations with current and former allies, and reaching out to erstwhile foes like Vietnam.

Deployments of military hardware also signal U.S. resolve to allies and partners. For example, the deployment of the advanced antimissile system known as the Terminal High-Altitude Area Defense system (or THAAD) in South Korea reaffirms America’s security commitment to a valuable ally in Asia. THAAD ostensibly went to the peninsula to protect the South from North Korea’s burgeoning arsenal of missiles. Yet the antimissile emplacements also quietly put Beijing on notice that the allies can counteract China’s ballistic-missile inventory.

The United States, moreover, has long pursued positive economic interests in Asia, a region to which 28 percent of U.S. goods and 27 percent of service exports flow annually. Those percentages exceed the shares going to the European Union and to the United States’ NAFTA partners, Mexico and Canada. The Obama administration, furthermore, is pushing a Trans-Pacific Partnership trade agreement that would join the United States with 11 other countries along the Pacific Rim. Through the TPP and other economic outreach, the administration is pursuing positive interests that conform to historic U.S. policy aims—namely opening markets while reducing barriers to American goods and capital.

The U.S. “pivot” to Asia, then, is founded on solid, rational strategic calculations. But the strategy also comes with significant caveats and dangers. For example, reallocating ships, aircraft, and munitions to the Asia-Pacific region weakens the U.S. Navy’s capacity to project power in the Mediterranean, the Persian Gulf, and other important theaters.

There could also be unintended consequences to pivoting to the Far East. Rebalancing the U.S. Navy, for instance, could unwittingly signal irresolution to rivals like Russia and Iran. President Vladimir Putin could interpret the pivot as a license to launch new adventures in Ukraine and the waters around Europe. The refugee crisis in the Mediterranean, where hundreds of thousands are fleeing Syria, Iraq, and other war-torn countries, provides a daily reminder of the instability emanating from the Middle East and South Asia.

Clausewitzian calculations, then, warrant an effort of intense magnitude and open-ended duration in the Asia-Pacific. But there are opportunity costs to the pivot. Taken to its extreme, the rebalance might impel Washington to triage other regions.

U.S. strategy in Iraq, on the other hand, provides an example of a strategy seeking equilibrium between an important but not vital political aim coupled with limited efforts to achieve the goal of defeating the Islamic State. One can argue that the precipitous withdrawal of American forces in 2011 created the conditions for ISIS to flourish. However, U.S. strategy is now carefully calibrated to uphold a balance between the costs and benefits of American support of the Iraqi government’s efforts to defeat the terrorist group.

The absence of domestic political support for another major U.S. troop commitment to Iraq compelled the Obama administration to devise a moderate and patient course of action promising a reasonable chance of success. The cornerstone of U.S. military strategy is an air campaign designed to assist allied forces on the ground while degrading and destroying the military and economic capacity of the Islamic State to hold territory.

This strategy has the added benefit of limiting the scale of U.S. commitments. Washington currently restricts the number of American ground forces to fewer than 5,000, most confined to logistical support and a stringent train-and-assist mission. This reduces the risk to American forces while strengthening Iraqi security forces. Meanwhile, a relatively small contingent of U.S. Special Forces has undertaken reconnaissance and narrowly targeted search-and-destroy missions. Collectively, these three operational strategies furnish crucial assistance to Iraq’s war against the Islamic State while limiting costs to the United States in blood and treasure.

Yet this moderate course of action also comes with risks. Critics argue that the administration’s approach is too risk-averse. They contend that this strategy allows ISIS to retain control of significant swaths of territory in both Iraq and Syria for some time, even as the terrorist group expands to other areas in the Middle East, Africa and South Asia.

While this critique merits serious consideration, the current strategy has much to commend it. By imposing restrictions on the size and scope of U.S. military actions in Iraq, the administration has compelled local and regional forces to bear the brunt of the fighting. This allows the United States to proffer a helping hand and demonstrate commitment to its ally while greatly reducing American liability.

Washington’s strategy toward ISIS may prolong the conflict and allow other, less savory actors like Iran to claim credit for military gains. But that seems like a reasonable tradeoff in a region that has cost Americans so dearly for so little tangible gain. Strategic triage, then, is not final. So long as a patient like Iraq survives being triaged—even in an enfeebled state—the physician can renew care in some form and degree.

The continuing American presence in Afghanistan provides the most troublesome example of how difficult it is to balance the costs and benefits of the status quo. President Obama recently announced that the U.S. military will keep 8,400 troops in Afghanistan until the end of his term. The president also authorized U.S. forces to expand their engagement and granted them greater flexibility to pursue enemy forces.

Taken together, these measures signal the prolonging of the fifteen-year American commitment to Afghanistan. The costs of the endeavor should give decision-makers pause. Some 2,365 U.S. servicemen and -women have perished in the conflict, while the estimated outlays far exceed $1 trillion. At the very least, the Obama administration should reevaluate whether the costs have exceeded the potential returns from a major commitment to a war that is seemingly unending.

Here a strategist might ask whether the cognitive bias of “sunk costs” has warped U.S. calculations. Economists warn against making decisions about future investments based on what has already been invested. Transposed to the strategic sphere, decision-makers must not invest more lives, treasure, and military hardware simply because they’ve already sunk so many lives, treasure, and hardware into an enterprise. Clinging to past investments flouts rationality.

Those gripped by the sunk-cost fallacy insist the Afghan war must continue in order to justify the sacrifices already made. The rise of the Islamic State in the aftermath of the U.S. withdrawal from Iraq, as well as the domestic political fallout, may be distorting the administration’s assessment of the value of the U.S. commitment to Afghanistan.

Lyndon Johnson famously disregarded the imbalance between the value of victory in Vietnam and the cost of attaining it. Johnson proclaimed, “I am not going to be the first American president to lose a war.” One wonders whether President Obama will utter some similar statement to explain his decision to remain tethered to Afghanistan. It is easy to add up costs, risks, and benefits, and conclude it is time to execute a strategic triage. But it is politically difficult, for a variety of reasons, to actually cut off support. This is true even when the costs have far outrun the potential benefits of remaining in Afghanistan.

Avoid Strategic Triage at Your Peril:

These three examples underscore the utility of strategic triage. Wise conduct of foreign policy requires constant reassessment on the part of all states—especially great powers such as the United States that must juggle a multitude of interests and commitments. The history of great powers is rife with examples of states that tried to do it all, everywhere, and frittered away their dominance by failing to retain a balance between resources and obligations.