American political leaders and foreign policy professionals have long debated the question of what considerations should have precedence in guiding the republic’s foreign policy. Realists assert that sober calculations of tangible national interests must be the dominant factor, even when that means compromising or even ignoring fundamental values. Sometimes they exhibit barely concealed scorn for the notion that moral considerations should have a high priority. Henry Kissinger often articulated that attitude. “A country that demands moral perfection in its foreign policy,” he argued, “will achieve neither perfection nor security.” Even John Mearsheimer, a reasonably cautious and ethical realist, once stated: “In the anarchic world of international politics, it is better to be Godzilla than Bambi.”

More idealistic types, on the other hand, contend that such an amoral approach isunworthy of a democratic republic founded on respect for inalienable rights. Susan Rice, national security adviser in the Obama administration, argued that children in countries torn by armed strife are “deserving of the same rights, the same security, and the same hope that our own children enjoy. Their future is bound up with our own. It is for their sake, and ours, that we stand fast for human rights. For their sake, and ours, we hold resolutely to our founding principles in this complicated and often dangerous world. And, it is for the sake of our common humanity and our shared future, that, even if imperfectly, we keep striving each day to build a world that is more just, more equal, more safe, and more free.”

Members of both factions have tended to use their preferred doctrine to advocate military alliances and outright interventions that might not be justified under the competing approach. The result is that, whichever of these doctrines gains dominance in the country at any given time, the result is often the same: military adventurism. Inflated concepts of national interests and unrealistic invocations of universal values have resulted in unnecessary and sometimes unsavory alliances and military missions.

Proponents of Washington’s cozy security relationship with autocratic regimes, such as those in Saudi Arabia and Egypt, like to style themselves as realists. They insist that the United States has key national interests in the Middle East, including combating terrorism, preventing political instability, and protecting the global oil supply. Such interests, they believe, are so important that they require Washington to make common cause with those regimes, even though they are corrupt and repressive.

U.S. leaders have concluded multibillion-dollar arms deals with Cairo and Riyadh in just the past few years, despite those governments’ abysmal human rights records. The Obama and Trump administrations even have backed the Saudi-led military intervention in Yemen, including refueling coalition warplanes and providing intelligence to assist them in striking their targets. The justification is that Yemen has become a haven for terrorists and Iran is attempting to create disruption in the region by backing the rebel Houthi forces. Moral considerations play little or no role in Washington’s policy regarding Yemen. The Saudi forces have committed multiple war crimes, yet U.S. officials don’t seem to care.

Making common cause with odious “friendly dictators” is nothing new. Throughout the Cold War, U.S. administrations maintained intimate security ties with several awful regimes. American political leaders fostered such cooperation with the likes of the Shah of Iran, Taiwan’s Chiang Kai-shek, Nicaragua’s Somoza family, Zaire’s Mobutu Sese Seko, South Korea’s Park Chung-hee and Chun Doo-wan, and the Philippines’s Ferdinand Marco, among others. In an example of rhetorical cynicism, U.S. officials routinely hailed those authoritarian figures, many of them tyrants, as members of the “Free World.”

However, the influence of the “values faction” in America’s foreign policy community is evident in other military-oriented policies that Washington has adopted over the years. It was nearly impossible to justify intervening in the wars convulsing the former Yugoslavia during the 1990s on the basis of U.S. national interests. Few proponents of U.S. involvement even made much of an attempt. Instead they insisted that the suffering that innocent civilians were enduring in Bosnia and later in Kosovo required the United States to take action against Serbian forces. That alleged moral obligation in the Balkans strengthened an embryonic doctrine, the Responsibility to Protect (R2P).

One of the first key foreign policy activists to invoke R2P was Samantha Power, who had written a seminal work on the Rwandan genocide. That episode had a profound impact on her perspective regarding U.S. foreign policy, as it did with other R2P advocates. Susan Rice would later say: “I swore to myself that if I ever faced such a crisis again, I would come down on the side of dramatic action, going down in flames if that was required.”

The argument that Power and other R2P supporters made was that America, as the global superpower and the model of a moral, democratic society, had an obligation to lead collective efforts to prevent any repetition of a Rwanda-style tragedy. That call played a major role in the Clinton administration’s decision to intervene militarily in both Balkan internecine conflicts.

The R2P rationale also was a crucial factor in the Obama administration’s 2011 decision to launch a humanitarian military intervention in Libya. Dennis Ross, a senior Obama administration adviser, warned that 100,000 people would be killed in rebel-controlled Benghazi if Libyan dictator Muammar Qaddafi succeeded in conquering the city. Such a monstrous toll would have been more than one-seventh of Benghazi’s population. Ross was not alone in expressing such inflammatory warnings. Other administration officials shared his fears. In her memoir, Secretary of State Hillary Clinton stated flatly: “We were looking at a humanitarian catastrophe, with untold thousands at risk of being killed.”

It was not surprising that the most passionate advocates within the administration for military intervention were Rice, Clinton, and NSC senior staff member and soon to be UN Ambassador Samantha Power—all outspoken fans of R2P. Qaddafi did not pose a credible threat to U.S. security or economic interests. Indeed, barely seven years earlier, Washington and its European allies had concluded an agreement with him to abandon Libya’s embryonic nuclear program in exchange for the lifting of U.S. and multilateral sanctions and the country’s readmission to international institutions. A war against Libya had to be sold on humanitarian, not national interest, grounds.

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Proponents of humanitarian wars usually are not content with mere rescue missions, however, as the Libya episode soon confirmed. George H. W. Bush’s December 1992 intervention in Somalia was a rare exception—at least initially. The situation in that fractured country was indeed dire, with tens of thousands of people already starving. Washington’s relief effort aimed at using the U.S. military to distribute food and take other measures to ease the widespread suffering. It did not seem to have an underlying geopolitical purpose, although those forces did ultimately become entangled in Somalia’s multi-sided political conflict.

In the case of Libya, the prevention of civilian casualties was, despite the Obama administration’s rhetoric, purely a secondary motive. Secretary of Defense Robert Gates notes in his memoirs that, “as the list of bombing targets steadily grew, it became clear that very few targets were off-limits and that NATO was intent on getting rid of Qaddafi.” The R2P doctrine’s implicit objective in Libya—and in other settings, such as the Balkans—was to thwart human-rights abuses by getting rid of murderous tyrants. Regime change is typically the underlying goal, not just humanitarian relief.

Not surprisingly, some enthusiasts for U.S. military crusades and dubious security associations are content to use either national interest or humanitarian justifications. Arizona’s Republican Senator John McCain is especially adept at invoking whichever argument seems to have the greater traction with American public opinion in a particular setting. Thus, he stressed the national interest rationale for invading Iraq to eliminate Saddam Hussein’s alleged arsenal of weapons of mass destruction. But he relied much more on humanitarian rationales to back the regime-change war against Qaddafi.

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Other proponents of frequent U.S. interventions try to meld national interest and idealistic values justifications. President George W. Bush adopted that approach explicitly in his second inaugural address when he asserted that in foreign policy, “America’s vital interests and our deepest beliefs are now one.” If taken seriously, his statement would mean that the two justifications for military interventions and security ties were nearly interchangeable. Indeed, in a February 2003 speech to the hawkish American Enterprise Institute on the eve of the Iraq War, the president insisted that “America’s interests in security, and America’s belief in liberty, both lead in the same direction.” In Iraq that mix led to a disastrous war.

Bush’s assumption defies both logic and history. Interests and values are not the same. There will nearly always be tension, even severe tension, between them. Franklin Roosevelt and Winston Churchill did not embrace an alliance with Joseph Stalin’s Soviet Union because their countries shared common values. They did so, despite the communist regime’s repulsive values and conduct, because all three countries confronted an existential threat to their security.

In foreign policy decision making, the consideration of national interests needs to be the first level of evaluation. The urgent task for the current generation of U.S. leaders is to adopt a more rigorous, coherent hierarchy of national interests. Because there are times when, for legitimate security reasons, it may be necessary to make ethical compromises, it is imperative to establish some standards to determine when a situation warrants making such sacrifices and when it does not. Three crucial factors come into play. First, what level of U.S. interest is at stake? Is it a vital interest? A substantial but less than vital interest? Or something more marginal? Second, how seriously is that interest threatened? Finally, just how odious is Washington’s prospective partner? The first consideration is the most important, but the others are far from minor.

In determining what kind of interest—security, economic, or political—is involved and how important it is to the wellbeing of the American people, it is essential to define the pertinent terms. Unfortunately, that is something U.S. officials often don’t do at all or do so in a perfunctory, slipshod fashion. But not all interests are equal; some are vastly more important than others, and threats to less important ones mandate greater restraint about making ethical compromises.

Determining the nature and level of national interests is a complex exercise, and the following is merely a rough guide. In general, though, interests can (and should) be divided into three broad categories: vital, secondary (or conditional), and peripheral. Each category warrants a different level of response from the United States.

Unfortunately, in both the Cold War and the so-called war on terror, U.S. leaders have been far too casual and expansive regarding the “vital interest” category. That is unfortunate on several levels, not least because such thinking provides a rationale for waging unnecessary, sometimes utterly foolish wars—while at the same time betraying American values by encouraging the embrace of repulsive regimes.

For any nation, but especially for the United States, truly vital interests are few in number. National survival is obviously the most important interest, but others include thwarting external threats to political independence, domestic liberty, citizen safety, and economic well-being. The level of security of those vital interests depends heavily on both the threat environment and the capabilities of a potential adversary.

America’s position is enviable on both counts. The United States may be the most secure great power in history. Not only does it benefit from having two vast oceans on its eastern and western flanks, which renders a large-scale conventional attack on the American homeland virtually impossible, but it has the luxury of dealing with an assortment of weak, and for the most part friendly, neighbors throughout the hemisphere. There is no country that even approaches being a serious military competitor in America’s neighborhood. In the Western Hemisphere, the United States is now and will be for the foreseeable future the utterly dominant strategic and economic player.

Even viewing the global security environment, it is difficult to identify many credible threats to America’s vital interests. Notwithstanding the rise of other powers, most notably China and India, the United States still enjoys a sizable economic edge and an enormous military advantage. Moreover, both of those rising powers have a considerable stake in maintaining decent relations with the United States.

Russia’s threat capability, outside the realm of nuclear weapons, is vastly exaggerated in American political discourse. Russia is a regional power with an economy roughly the size of Spain’s. The nuclear dimension can’t be ignored, but such weapons are useful only for deterrence, unless a country wishes to commit national suicide, and there is no sign that Russian rulers contemplate going down that path. A similar avoidance of panic and threat inflation should apply to alleged security threats that so-called rogue states such as Iran and North Korea pose to vital U.S. interests. Even if they possessed small arsenals of nuclear weapons, such states are deterrable, barring the unlikely scenario of a regime willing to commit suicide by launching an attack against a nation with more than 2,000 nuclear weapons and highly sophisticated delivery systems.

Terrorism, the other so-called threat to America’s vital interests, is even more overhyped. Hawks frequently assert that terrorist groups pose an “existential threat” to the republic. That is nonsense. Terrorism is and always has been the weapon of weak parties, and the current crop of stateless Islamist groups is no exception. An existential threat means a menace to a nation’s very survival or independence. Those groups may strike fear in the hearts of people, but they do not pose an existential threat even to small countries, much less to the world’s superpower.

The bottom line is that vital interests are few, and serious threats to those interests are rare. And in most cases the United States, by itself, would be able to neutralize such threats. If America’s vital interests truly become imperiled, policymakers might have to downplay concerns about values, just as they did when Roosevelt and Churchill established the Grand Alliance with Stalin. But nothing like that danger exists now or seems plausible in the foreseeable future.

The real challenge for U.S. leaders is to do a better job of assessing America’s response to the two categories of lesser interests—secondary and peripheral. Secondary interests are assets that are pertinent but not indispensable to the preservation of America’s physical integrity, independence, domestic liberty, or economic health. For example, even if one of the regions outside the Western Hemisphere that had substantial strategic and economic importance to the United States came under the domination of an adversary, it would not automatically threaten the vital interests of the United States. America could still do reasonably well, for instance, even if China became the hegemonic power in East Asia, as long as Europe and the South Asia/Persian Gulf region remained outside Beijing’s orbit. Chinese dominion over East Asia, however, would make for a significantly more uncomfortable strategic and economic environment for America, and U.S. leaders understandably will want to prevent such an outcome. There are limits, though, to how far policymakers should go in adopting measures to contain a rising peer competitor such as China or to protect secondary American interests.

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Unlike the defense of vital interests, the defense of (or promotion of) secondary interests justifies only modest exertions. Washington might deem it beneficial to encourage and lend political and diplomatic support to the efforts of friendly countries to resist the growing power of an emerging, adversarial regional hegemon. In some instances, the transfer of militarily relevant technology, and even direct arms sales, to such countries might be warranted. But, whereas the United States must be willing even to risk war to defend vital interests, that stance is usually not warranted when secondary interests are involved.

Such a distinction also applies to the willingness to cooperate with unsavory foreign partners. Although America has some clear interests in the Middle East, retaining alliances with countries such as Egypt and Saudi Arabia—and even an increasingly autocratic Turkey—is unwarranted. When secondary rather than vital interests are at stake, the bar should be higher for aligning with such allies. It might be too much to insist that a partner be a full-fledged democracy or have a squeaky-clean record on corruption and human rights, but there is still a need for limits to Washington’s tolerance.

Risk-benefit and cost-benefit calculations shift further in the direction of caution when the matter involved is one of peripheral interests. That category consists of assets that marginally enhance America’s security, liberty, and economic well-being, but the loss of which would be more of an annoyance than a significant blow. The existence of a hostile regime in a mid-size country in Latin America (Venezuela comes to mind) is an example of a threat to a peripheral interest. Another would be the onset of greater political turbulence in the Middle East or Persian Gulf, given the probable impact on oil prices. Washington shouldn’t be indifferent to such matters, but there is nothing at stake that normally requires more than diplomatic exertions. It certainly doesn’t constitute a valid strategic rationale for a military intervention.

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A rational, systematic assessment of U.S. interests logically leads to a foreign policy of restraint. There are actually few instances when Washington should contemplate using military force to defend its tangible interests. And policymakers need to reject outright the concept of involving the republic in warfare to protect foreign populations from human-rights abuses or chronic misgovernment. Those problems are tragic for the people involved, but they should never be a casus belli for America.

R2P advocates, of course, insist otherwise. They argue that the United States has a moral (and as a member of the United Nations, a legal) obligation to rescue abused civilian populations. There are three major problems with that approach.

First, it creates an incentive to highlight abuses in order to prod the United States into military action, even when the republic has few if any substantive interests at stake. Proponents of humanitarian intervention tend to portray the typical bloodshed of warfare as outright genocide. Such hype was especially evident during the Balkan wars, when interventionists repeatedly warned that genocide was taking place. Yet the total number of fatalities in Bosnia from three years of three-sided warfare was barely 100,000—and half were military casualties. Such a toll actually was on the low side for a civil war of that duration.

The use of the genocide term was even less appropriate in Kosovo, where the toll appears to have been approximately 2,100 victims during some 13 months of fighting. If such a limited number of fatalities constitutes genocide, then virtually every conflict involving different religious, ethnic, or racial groups would be genocide, and America would be conducting humanitarian interventions constantly.

A second problem with invoking universal values as justification for military crusades is that U.S. meddling frequently makes situations worse, not better. That is certainly what happened in Libya. Qaddafi was a brutal and corrupt ruler, but post-Qaddafi Libya is a cauldron of chaos. The country has become a Somalia on the Mediterranean, with numerous thuggish militias and three rival governments vying for power. Nearly a million refugees have fled the violence, most of them in overcrowded, leaky boats trying to cross the Mediterranean to reach safety in Europe. Tens of thousands have died on the way. The U.S.-led humanitarian war produced a humanitarian catastrophe.

Finally, and most importantly, U.S. leaders have neither a constitutional nor a moral mandate to involve the republic in unnecessary wars, even if they have noble motives to rescue at-risk foreign civilians. The president and other officials have a fiduciary responsibility to defend the security and liberties of the American people. They have no right to put the fortunes—and especially the lives—of Americans in danger to defend foreign populations from either external or internal abuses, tragic as they might be. Involving the United States in wars when the nation’s vital interests are not imperiled is a violation of that fundamental principle.

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In deciding whether it is appropriate to wage an armed conflict, policymakers should ask whether that step is truly necessary to protect the vital interests of the American people. If the answer is yes, consideration of values becomes secondary. Even then, U.S. leaders should strive to minimize the need for alliances with especially vicious security partners. When only secondary or peripheral interests are involved, the option of resorting to war should almost always be off the table. The appropriateness of temporary alliances with security partners also needs to be scrutinized more carefully in such instances. Cooperating with nasty regimes might be unavoidable when American vital interests are menaced, but such associations should be spurned when it means compromising important values to protect lesser interests. All too often during the Cold War and since, U.S. leaders have failed to make that distinction.

National interests and values should be used as screening measures for America’s foreign policy conduct. Both should serve as barriers to unwise, unnecessary, and morally inappropriate actions on the world stage. Properly applied, they are a blueprint for keeping the republic at peace, in marked contrast to the nearly continuous military adventurism of recent decades.

Ted Galen Carpenter, a senior fellow in defense and foreign policy studies at the Cato Institute, is the author of 10 books on international affairs, including The Captive Press: Foreign Policy Crises and the First Amendment.