This article was originally posted at National Review.

When the Western Allies needed a supreme commander for the newly created North Atlantic Treaty Organization in 1949, they unanimously agreed that Dwight Eisenhower was “the only man” for the job. The soldier most responsible for the liberation of Western Europe would help make sure that the Soviet Red Army — which already had enslaved Eastern Europe — would not advance an inch further. “I rather look upon this effort,” he said, “as about the last remaining chance for the survival of Western civilization.”

Today millions of Republicans are cheering the nomination of Donald Trump as their presidential candidate, giddy over the fact that the business mogul has no political experience, not a shred of diplomatic experience, and lacks even a basic knowledge of America’s military assets, not to mention its national-security challenges. Eisenhower, also a political novice, nonetheless marshalled every ounce of his military and diplomatic knowhow to guide the nation safely, over eight years, through some of the most dangerous moments of the Cold War.

During the 1952 presidential campaign, the Republican nominee made a surprise announcement: “I shall go to Korea.” The Korean War, mired in stalemate and increasingly unpopular, was claiming 2,000 U.S. soldiers a month. Eisenhower, the former Supreme Commander of the Allied Forces in Europe during the Second World War — the man who planned the U.S.-led invasion at Normandy — believed he needed a first-hand look to see if this latest war was winnable. He determined that it wasn’t, and quickly brokered an honorable peace.

Within months of assuming office in 1953, Ike ordered a review of Harry Truman’s Containment Doctrine that redefined U.S. foreign policy as an ideological struggle against international Communism. Project Solarium, as it was called, produced recommendations from three separate committees — ranging from continuing with containment to adopting a much more confrontational strategy.

“The president had been sitting and listening to each one of the presentations, not taking a single note,” recalled General Andrew Goodpaster, Ike’s adviser. “He then rose and spoke for forty-five minutes, summarizing the three presentations and commenting on the specific strengths and weaknesses of each one.”

Eisenhower said he’d reject any strategy that couldn’t gain the support of America’s allies, or which made a general war with the Soviets more likely. He argued that the build-up in U.S. military strength must not trigger a total breakdown in international relations; needlessly forcing a showdown would be a tragic error. Thus Eisenhower embraced containment, pledging to minimize the risk of war while preventing Soviet expansion in Europe. George Kennan later recalled that the president demonstrated “intellectual ascendancy over every man in the room . . . He had such a mastery over the military issues involved.”

Imagine, if you can, Donald Trump exercising the mental discipline required to analyze a complex national-security crisis. Imagine him, playboy who dodged the military draft, showing mastery over the military issues involved. Yes, it is unimaginable.

Recall that by 1954, Eisenhower faced strong pressures to send American soldiers into Vietnam. The French were losing their battle against Communist insurgents to re-establish their control in Indochina. They desperately wanted American help in the form of boots on the ground. Pressure also came from Eisenhower’s cabinet — including Vice President Richard Nixon — to rescue the French effort and stop the spread of Communism. Secretary of State John Foster Dulles, along with Ike’s Air Force Chief of Staff, even suggested that the United States drop three small atomic bombs on the Viet Cong.

Eisenhower was appalled. “You boys must be crazy,” he said. “We can’t use those awful things against Asians for the second time in ten years. My God.” Although Eisenhower warned of a “domino theory” in Southeast Asia if Vietnam fell to the Communists, he opposed direct U.S. military involvement. The French emphasized their common struggle in the Cold War, but Ike considered the French army a “hopeless, helpless mass of protoplasm.” In the end, he provided military assistance, but refused to send American troops into combat: “I cannot conceive of a greater tragedy for America than to get heavily involved now in an all-out war in any of these regions.”

When a war scare broke out in 1955 over Communist Chinese aggression in the Formosa Strait, American hawks again raised the specter of nuclear weapons in a preventive strike “to destroy Red China’s military potential and thus end its expansionist tendencies.” The Secretary of State claimed the Chinese were “more dangerous and provocative of war” than Adolf Hitler. Eisenhower rebuked them, telling reporters that a nuclear war against China would create human misery on a massive scale. “What,” he demanded to know, “would the civilized world do about that?”

How would a President Trump, who speaks admiringly of Vladimir Putin while promising to destroy the Islamic State in short order, approach a crisis involving Russia, North Korea, Iran, or Syria? How would Trump’s cavalier attitude toward NATO — he’s happy to see it dismantled — improve the security of the United States and its democratic allies? How, exactly, will his appalling ignorance of foreign affairs help him make life-and-death decisions?

Diplomatic experience does not always translate into good judgment, of course, as Hillary Clinton’s record of incompetence and failure abroad makes blazingly clear. But real-world experience is a pre-requisite for effective leadership in a violent and unstable era: It offers the statesman a dose of moral realism, helping him to navigate between pacifist dreams and militarist adventures.

In his farewell address, Eisenhower famously warned against the encroaching influence of the “military-industrial complex.” Yet he did not shrink back from strengthening U.S. military power relative to the Soviet Union. “As one who has witnessed the horror and the lingering sadness of war—as one who knows that another war could utterly destroy this civilization which has been so slowly and painfully built over thousands of years—I wish I could say tonight that a lasting peace is in sight.”

No leader was better prepared — emotionally, morally, intellectually — to safeguard America’s national security during a Cold War that at any moment threatened to become hot. As Eisenhower once told an aide: “God help this nation when it has a president who doesn’t know as much about the military as I do.”

Yes, in the season of Trump vs. Clinton, God help the United States of America.

Joseph Loconte is an associate professor of history at the King’s College in New York City and the author of A Hobbit, a Wardrobe, and a Great War: How J.R.R. Tolkien and C.S. Lewis Rediscovered Faith, Friendship, and Heroism in the Cataclysm of 1914-1918.