Nuclear escalation on the Korean Peninsula would have gone terribly for everyone involved. The United States would have caused dreadful pain to uncertain strategic advantage, potentially pushing the Communist powers to escalate.  The physical and human terrain of Korea would have endured awful suffering. And perhaps most importantly, the world would have lost the nascent nuclear taboo, a sense among policymakers that atomic weapons differed in some meaningful sense from other kinds of explosives, and that their practical use portended something momentous.

In 1950, as U.S. forces retreated from China’s onslaught across the Yalu River, General Douglas MacArthur called for strategic air attacks against China. Many believed that this would necessarily include the atomic bomb, America’s “asymmetric advantage” of the time.

America’s large arsenal of atomic weapons, and the fleet of strategic bombers necessary to deliver those weapons, was the central military advantage that the US enjoyed over the Soviet Union in 1950. The large, battle tested Red Army remained in Eastern Europe, capable of moving west on short notice. Many believed that only America’s ability to destroy the Soviet heartland with nuclear weapons held the Russians back. Many also believed that Moscow had orchestrated the war on the Korean Peninsula.

So why didn’t the United States use the bomb in Korea?  What if it had?

The Situation:

The Korean War witnessed three critical inflection points in 1950. The first was North Korea’s full-scale invasion across the thirty-eighth parallel in June, an action which escalated a conflict that had broiled for several years. The U.S. landing at Inchon in September ended the North Korean offensive, turning the tables and putting the Communists on the defensive. Then, in late October, the intervention of China’s People’s Liberation Army ended the Allied offensive, and forced UN forces back beyond the thirty-eighth parallel.

It was at this point that MacArthur called for attacks into China, and many in the United States began to demand the use of the atomic bomb. Despite the remarkable progress that the Soviets had made on their own bomb program, the United States still enjoyed a huge advantage in total atomic weapons, and in delivery systems.

Strategic or Tactical:

In 1950, the U.S. defense establishment had yet to work out the elaborate system of planning, development, and mobilization that would divide nuclear weapons by type and purpose, and had not fully integrated atomic weapons into its conventional warfighting plans. Nevertheless, the United States would have faced a choice between using atomic bombs as “tactical” or “strategic” weapons.

Strategic attacks would have concentrated on Chinese staging areas, industrial sites, and political targets, aiming to either bring about the collapse of the PRC or force it from the war. Mao Zedong expected something of this nature when he chose to commit the People’s Liberation Army to the war on the peninsula. Given the size of China’s population and the dispersed nature of its industry, such a campaign would have required a great many of the rudimentary atomic warheads of the time.

And indeed, even the strategic use of atomic weapons against Chinese targets would have generated criticism from within the U.S. defense establishment. For many within the establishment, China was only a proxy for broader Soviet efforts to destabilize the West and break the nascent system of containment.  Wasting warheads on Chinese targets would have left Soviet industry relatively untouched, and thus capable of generating additional proxy wars across the globe. Committing the US Air Force’s fleet of B-36 “Peacemakers” to a general strategic campaign against China would not only have tipped the hand of the Strategic Air Command, it might- given the questionable defensive capabilities of the bombers- have left the US with few or no options for striking directly into the Soviet Union.

What if the United States had instead concentrated on using nuclear weapons in a tactical manner?  First things first, U.S. nuclear strategy did not envision using the nation’s relatively small nuclear arsenal against merely “tactical” targets; the United States had few enough weapons (and few enough delivery systems) to waste them on the deployed enemy forces. We had extraordinarily little information on the actual tactical and operational effect of nuclear weapons on the battlefield.  Certainly, Chinese and North Korean command centers, logistical centers, and troop concentrations would have fared poorly under nuclear assault.  But then the United States enjoyed major advantages in the airspace above Korea in any case, and regularly subjected Communist forces to air attack. Atomic weapons surely would have helped, although potentially at the cost of permanently delegitimizing the Seoul government (which would have invited the nuclear destruction of its own homeland).

War Situation:

Recent work on the Korean War has revealed other reasons why the United States resisted using the atomic bomb. While some believed that the United States exercised unilateral restraint in the war, in fact both sides carefully husbanded their strength, and took care moving up the escalatory ladder.

American military authorities feared that an escalation of the war would make the situation on the peninsula untenable. Far from exhausting its strength, the People’s Republic of China maintained a substantial reserve of ground and air forces that it could throw into the fight if the United States decided to step up the war.  Perhaps more importantly, the Soviet Union could exert a vastly greater influence on the conflict, either through a stepped up transfer of equipment to China and the DPRK, or through the direct deployment of Soviet ground, air and naval forces. If the US decided to go all out, the Red Army had more than enough strength to clear continental East Asia of U.S. forces, and perhaps to cut U.S. lines of retreat from Korea.

The Final Salvo:

Nuclear escalation on the Korean Peninsula would have gone terribly for everyone involved. The United States would have caused dreadful pain to uncertain strategic advantage, potentially pushing the Communist powers to escalate.  The physical and human terrain of Korea would have endured awful suffering. And perhaps most importantly, the world would have lost the nascent nuclear taboo, a sense among policymakers that atomic weapons differed in some meaningful sense from other kinds of explosives, and that their practical use portended something momentous.

Robert Farley, a frequent contributor to TNI, is author of The Battleship Book. He serves as a Senior Lecturer at the Patterson School of Diplomacy and International Commerce at the University of Kentucky. His work includes military doctrine, national security, and maritime affairs. He blogs at Lawyers, Guns and Money and Information Dissemination and The Diplomat.

This first appeared in October 2016 and is being reprinted due to reader interest.