Donald Trump has done America a huge favor.

During the Detroit presidential debate two weeks ago, Trump inadvertently injected into the campaign a topic as tragic in its absence as it is vital to the question of commander-in-chief suitability. Fox News anchor Bret Baier asked Donald Trump what he, as president, would do if the U.S. military refused to execute his orders—that is, targeting terrorists’ families and “a hell of a lot worse than waterboarding.” The business tycoon responded with a confidence bordering on swagger: “They won't refuse. They're not going to refuse me. Believe me. . . . If I say do it, they're going to do it. That's what leadership is all about.”

CNN’s Jake Tapper re-litigated the point last week in Miami. Trump budged and proposed an elegant work-around. Instead of forcing the military to carry out illegal orders, he said, “We better expand our laws . . . They [ISIS] are laughing at us, believe me.”

Although this back and forth has so far borne little fruit, the GOP front-runner did cast a spotlight on the single most important element in any national-security apparatus: civil-military relations. Anyone interested in gauging who is best suited to command America’s military should capitalize on Trump’s rhetorical door opening and challenge the 2016 presidential candidates to articulate their vision for civil-military relations. Every American presidency has had to assuage civil-military tensions. The next president will doubtless be thrust into the same crucible.  

Why We Should Care

The civil-military problematique is inextricably linked to American freedom and security. The very power a polity gives a military to vanquish its foes and secure its global interests could, paradoxically, enable the military to prey on the society for which it was created to protect. Coup d'état is the traditional worst case scenario. Conversely, a military neutered for fear of tyranny couldn’t deter external aggression. A more plausible script would see a military, hell-bent on coercing foreign adversaries, drain society of its resources. Yet another concern is that a nefarious military could entangle a nation in wars deemed inimical to society’s interests. The list goes on. Peter Feaver, the Duke political scientist, explains the civil-military balancing act:

“The military may be best able to identify the threat and the appropriate responses to that threat for a given level of risk, but only the civilian can set the level of acceptable risk for society. The military can propose the level of armaments necessary to have a certain probability of successful defense against our enemies, but only the civilian can say what probability of success society is willing to underwrite. . . . The military assesses the risk, the civilian judges it.”

The United States is no stranger to civil-military discord. Harry Truman sacked Gen. Douglas Macarthur in 1951 to avoid all-out war with China. In 2010, Barack Obama relieved Gen. Stanley McChrystal of his Afghanistan post to preserve “the military chain of command and respect for civilian control over that chain of command.” More recently, CENTCOM analysts have alleged that supervisors manipulated their intelligence product to mask military failures in the fight against ISIS.

For the civilian president, navigating civil-military relations is a delicate art with monumental consequences. At the outset of the Cuban Missile Crisis in October 1962, the Joint Chiefs of Staff sought from John F. Kennedy a clarification on their rules of engagement. Gen. Maxwell Taylor and Gen. Curtis LeMay, then chairman and air force chief of staff respectively, extracted from Kennedy tacit permission to retaliate if any direct action befell U.S. servicemen. Days later, when the Soviets fatally downed Maj. Rudolf Anderson’s U2 over Cuba, the generals returned to the Oval Office, hoping to execute the course of action they favored all along—invasion and Castro decapitation. Kennedy made a judgment call. In the face of his generals’ appeals, he retracted his previous acquiescence. By resisting the urge to retaliate, Kennedy afforded the blockade and diplomacy the time needed to resolve the crisis without further bloodshed.

The civil-military bargain is what makes America America. It is the essence of our national security, intricately woven into the fabric of our power. There is, arguably, no better litmus test for commander-in-chief potential.

The Soldier and the State

Thoughtful voters wishing to identify which of their party’s candidates is most capable of preserving America’s strategic interests abroad would be well served by a quick dive into the civil-military-relations canon.

To this day, the political scientist Samuel Huntington’s classic work The Soldier and the State and his theory of “objective control” constitute the dominant model of civil-military relations in liberal democracies. The most prudent form of civilian oversight over the military, in his view, is that which maximizes the professional soldier’s capacity to fulfill his/ her central function—the “management of violence”—by isolating military leaders from politics and minimizing civilian micromanagement in military affairs. For Huntington, an effective civil-military relationship requires carving off for the military an operational sphere independent of politics. The civilian leader, in exchange, retains unquestioned final authority.

The sociologist Morris Janowitz identifies a distinction between the glory-seeking military leaders of old and the meticulously rational military managers that he approvingly observes have come to prominence. Whereas objective control may have been well suited to the conventional warfare that defined two world wars, the increasingly unconventional forms of warfare that emerged during the 1960s and 1970s led Janowitz to characterize the line separating military and nonmilitary establishments as permeable.

The political scientist Samuel Finer, in contrast, asserts that, if too narrowly defined, the formal subordination of the military to its civilian counterparts breeds the unintended consequence of a civilian leadership far too deferential to the awe-inspiring expertise of military professionals. Even more cynical than Finer, the military historian Russell Weigley rejects strategy as infeasible and argues that it is nearly impossible for civilian leaders to employ war as “a disciplined tool of policy rather than an autonomous force.”

In Supreme Command, Eliot Cohen contends that the degree of civilian intervention in military affairs should be a question of prudence, not principle, thereby fostering a healthy amount of civilian scrutiny and direction. Cohen infers from the military theorist Carl von Clausewitz that “all activity in war [has] potential political consequences and repercussions, and that every effort must therefore be made to bend war to serve the ends of politics.” He concludes that the crucial ingredient of civil-military relations is an “unequal dialogue.” The boundaries between political ends and military means, Cohen warns, are less certain and more malleable than Huntington suggests; therefore a carefully calibrated, dialectical (but not equally weighted) intercourse must continually exist in order to preserve the nation’s strategic interests abroad.

In the same vein, Feaver speaks to the “blurry line between advising against a course of action and resisting civilian efforts to pursue that course of action.” The Vietnam War provides many vivid examples. H. R. McMaster’s Dereliction of Duty lambasts Robert McNamara for his distrust of the military and excoriates the Joint Chiefs for not expressing dissent with enough conviction.

Supreme Command captures a sentiment reminiscent of one conveyed four decades prior by Britain’s greatest living historian, Sir Michael Howard. In his inaugural lecture as Professor of War Studies at King’s College London in 1964, Howard argues, “Politics must now interpenetrate military activity at every level as thoroughly as the nervous system penetrates the tissues of a human body, carrying to the smallest muscle the dictates of a controlling will.” Oxford military historian Sir Hew Strachan further reminds us that “the principal purpose of effective civil-military relations is national security; its output is strategy.”

The Night of the Generals

A diseased civil-military balance during the George W. Bush administration contributed to America’s astrategic invasion of Iraq.

Secretary of Defense Donald Rumsfeld and his deputy, Paul Wolfowitz, were irreconcilably distrustful of the military. Together, they created a climate of intolerance, which stifled strategic thinking and precluded constructive dissent. They treated their military counterparts and subordinates with either veiled condescension or overt disrespect. Few active-duty officers challenged them; those who tried did so to no avail and at great personal cost.

Gen. Eric Shinseki, then Army chief of staff, told the Senate Armed Services Committee in early 2003 that “several hundred thousand” troops would be necessary to tame Iraq. Wolfowitz responded the following day by publicly disparaging Shinseki’s estimate as “wildly off the mark.” Rumsfeld made an example out of Shinseki and named his successor a year in advance of the four-star’s scheduled retirement, thus delegitimizing his remaining authority. Never mind that Shinseki’s assessment would be vindicated by a growing insurgency in Iraq months later; the military brass received the message loud and clear. Three years on, not a single active-duty general had followed Shinseki’s example.

Retired Gen. Anthony Zinni, once head of CENTCOM, expressed his displeasure with Iraq policy publicly and often. He explained to the journalist Fred Kaplan that, although many officers chose not to challenge Rumsfeld out of fear, many others observed the concept of objective civilian control with a principled orthodoxy and, therefore, were ethically opposed to questioning their civilian superiors. Ironically, the military’s Huntingtonian understanding of civil-military relations censored its criticism of a defense secretary who was blatantly violating two core tenets of that same theory—ensuring the military an adequate voice and refraining from micromanagement. The military’s Huntingtonian inclinations and Rumsfeld’s (likely unconscious) adherence to Finer’s distrustful school of thought combined to corrode Washington’s ability to generate, let alone prosecute, a sound strategy in Iraq.