“Allied commanders were aghast. As one naval officer involved in the planning famously recalled, ‘we drew up a list of every natural and geographic handicap—and Inchon had ’em all.’”

By Walter Topp

THE WAR WAS going badly for North Korea, and it was about to get worse.

It was Sept. 14, 1950 – barely 11 weeks after Pyongyang’s June 25 invasion of South Korea. The North’s military planners had expected that it would take a month to crush the army of the Republic of Korea (ROK) and reunify the peninsula under the communist government of Kim Il-Sung. But now it was nearly autumn and the South’s forces and their American allies still held a toehold around the port of Pusan.

North Korea had not prepared to fight a long conflict, especially one against an enemy that had complete control of the air and sea.

At first, the communist invasion had gone exactly as planned. The North’s army was well-equipped, better trained and more experienced than South Korea’s forces. It had quickly smashed through the southern defences and driven the disorganized and demoralized survivors 150 miles south toward the bottom tip of the peninsula where they would surely be trapped and annihilated.

But Pyongyang’s timetable had been upended catastrophically when the United States intervened with air, sea, and ground forces in July. Neither the North, nor its reluctant backers in Moscow and Beijing, believed that the United States would respond to the invasion militarily.

Yet within 72 hours of the invasion, U.S. President Harry S. Truman ordered American air and naval forces in the Far East to intervene. The White House believed, albeit incorrectly, that the Soviet Union was directing the North Korean invasion and feared that the onslaught across the 38^th Parallel might be the opening move in a world-wide communist offensive. Washington’s swift reaction shocked Pyongyang and its Soviet and Chinese patrons.

On July 3, 1950, U.S. carrier-based warplanes kicked off an air campaign against North Korean targets. American ground forces – although shamefully ineffective at first – arrived in increasing numbers and showed growing competence. Supplies and reinforcements flowed through Pusan and the Allied forces steadily gained strength, finally halting the North Korean advance. Pyongyang’s efforts to win a speedy victory had failed; unless the communists could somehow regain the initiative, the conflict promised to be a protracted one.

One Last Push

On Sept. 1 – weeks after the war was supposed to be over – North Korea launched its last big push against the U.S. and ROK lines surrounding Pusan. As part of what would become known as the Great Naktong Offensive, the communists threw everything they had left at the Allied perimeter. It wasn’t enough.

Two months of steadily increasing U.S. air strikes against North Korean supply lines, along with stiffening resistance by American and South Korean ground forces, was bleeding Pyongyang’s army dry. To launch their new offensive, the North’s generals would have to strip troops away from newly captured territory, including the vital port of Inchon. Thousands of untrained conscripts, hastily pressed into service from “liberated” areas of South Korea were also suddenly thrust into battle around Pusan.

Though weakened by appalling casualties and shortages of food, ammunition and fuel, the North Koreans pressed on. Initially, the attackers made gains and even broke through in places. But for every gap opened, American and South Korean forces threw the communists back.

With a multinational United Nations emergency force being assembled and the North stalled, most expected that an Allied counter-offensive at Pusan might break the stalemate and force the invaders back up the peninsula. In fact, the supreme Allied commander in Korea, U.S. Army general Douglas MacArthur, envisioned a different strategy to force an even speedier conclusion to the fighting.

The hero of the Pacific War proposed a massive amphibious landing – codenamed Operation Chromite – targeting the South Korean port city of Inchon.

Amazingly, the communist commanders anticipated MacArthur. The general famously conducted a number of seaborne landings during the Second World War to bypass Japanese strongpoints on New Guinea and in the Philippines and Pyongyang fully expected a similar Allied assault at Inchon. In fact, the operation would turn out to be one of the worst-kept secrets of the entire Korean War.

Operation Common Knowledge

Before the conflict was even a week old, MacArthur ordered his staff to begin planning an amphibious assault at Inchon to relieve pressure on Allied forces as they retreated down the peninsula. This proposed landing, codenamed Operation Bluehearts, was to have taken place before the end of July.

Unfortunately for MacArthur, Bluehearts was canceled as the emergency at Pusan worsened and every last reinforcement that could be mustered was sent to shore up the perimeter there. But once the crisis subsided in August, the plan would be resurrected as Operation Chromite. By late summer, MacArthur was laying the groundwork for Chromite in earnest.

For the operation to succeed, the general needed troops, transport ships, landing craft and enough supplies for a major landing. Gathering it all would require hundreds of military planners, logisticians and schedulers from staffs in Tokyo, Pearl Harbor, Washington D.C., and a half-dozen allied capitals. Hundreds of civilians in Japan and other locations were contracted to provide supplies or services in support of the operation. Marine reservists were recalled, supplies were stockpiled and preparations were made to use Japanese-crewed landing ships for the assault. The scope of activity all but guaranteed that even the most obtuse observer could divine what was going on. In fact, security was so lax for Chromite that U.S. officers in Tokyo began referring to the planned landing as “Operation Common Knowledge.”

Mao’s Warning Ignored

Documents captured in Pyongyang later in the war showed that the North Koreans knew full well about the landing at Inchon before the end of August, but could do little to stop it. Chinese intelligence had detected the buildup and the chairman of the People’s Republic personally passed the details along to North Korean leader. But the communists lacked the strength to both defend Inchon and simultaneously break the Allied lines at Pusan. The North’s commanders had already stripped the defences along the coasts and elsewhere to reinforce their offensive far to the south. Although Pyongyang had plans to mine the harbour at Inchon, they never got to it. Yet even largely undefended, capturing Inchon was still going to be no easy task for the Americans.

The Worst Possible Place

While MacArthur’s plan for the landing might have been more of a conventional move than a stroke of genius, his fierce conviction that Inchon was where the landing must occur was, in fact, inspired.

The general could not have found a physically less suitable landing area for such an assault.

The target was miles from the open sea and could be reached only after navigating a narrow 10-mile long channel, which could be mined and defended by coastal batteries on either shore.

Inchon itself was protected by a rugged little island called Wolmi-Do, which would have to be captured prior to the main landing. Any assault on the fortifications there would alert the North Korean defenders on the mainland.

Worse, the tides off Inchon fluctuated wildly, rising as much as 32 feet, and were only optimal for an amphibious operation about two days a month.

There were no beaches at Inchon; the landings would have to carried out along two stone sea walls some four miles apart, which would divide the invading forces. The walls rose as high as eight feet above the decks of the landing craft in some places, meaning assault troops would need ladders to climb ashore.

Once on dry land, the attackers would find themselves in the middle of a city and could expect bloody street-to-street combat.

Not surprisingly, Allied commanders were aghast. As one naval officer involved in the planning famously recalled, “we drew up a list of every natural and geographic handicap—and Inchon had ’em all.”

Yet MacArthur was adamant that despite the obstacles, coming ashore at Inchon would place his forces in the best possible position to cut the enemy supply lines south and decimate the North Korean army besieging Pusan.

“We shall land at Inchon and I shall crush them,” he declared on Aug. 23.

His forceful defense of the strategy won over the skeptics, which included his nominal bosses on the Joint Chiefs of Staff.

Building the Force

The physical challenges were only the start of MacArthur’s problems.

The general also had to assemble an armada of ships to bring his army ashore. In the five years since the end of World War Two, the United States had junked the most successful and best-equipped amphibious force in history. By the time North Korea invaded the south, the U.S. Marine Corps had shrunk from 474,000 troops in 1945 to just over 75,000 in 1950. The Navy’s demobilization of its amphibious fleet was even more drastic. Within three years of VJ Day, its strength had plummeted from 3,000 ships to just 148.

MacArthur needed more than 40,000 men for the assault and most of the readily available combat troops had already been sent to hold the line at Pusan. To amass two more divisions of troops, the Pentagon would dip into the nation’s strategic reserves worldwide, reducing America’s ability to fend off another attack elsewhere. Thousands of Marine reservists were activated, the army’s half-strength Seventh Division was bolstered by stripping units from other commands, and as many as 8,000 untrained South Korean conscripts were added to the invasion force.

There was still the problem of landing ships. The navy lacked the transports to bring the two divisions ashore, so MacArthur assigned 15 LSTs (landing ship, tanks) and two cargo ships that had been decommissioned and turned over to the Japanese in 1945. Much of the specialized equipment needed for an amphibious landing had been removed by the new owners and was in deplorable condition. The Navy quickly recommissioned the ships, made some hasty repairs, assigned new commanding officers – although most were frighteningly inexperienced – and added a few signalmen and quartermasters to the Japanese crews to assist with communications and beaching operations. Smaller landing craft were brought out of storage and reactivated and experienced sailors were flown out from the United States to operate them.

In the end, MacArthur’s Inchon assault force included the First Marine Division, the Seventh Infantry Division, several units of ROK troops, and corps-level support units, including artillery; supported by a multi-national naval force of 261 ships comprised of amphibious ships, aircraft carriers, cruisers, destroyers, fire support ships, and minesweepers.

There would, of course, be no time for a rehearsal of the operation, and many of the troops were scarcely trained.

Amazingly and in spite of the long odds, the landings were superbly executed. Less than 90 days from North Korea’s surprise invasion, MacArthur, the U.S. and ROK militaries, along with a handful of allies, had turned back the North Korean attackers at Pusan and delivered a powerful counterstroke at Inchon.

Another Chinese Warning

As MacArthur had predicted, the landing faced little opposition and U.S. casualties were relatively light – 225 killed and 800 wounded. Despite explicit warnings from the Chinese that an invasion was coming, the North Koreans failed to organize an adequate defence at Inchon. Pyongyang gambled that they could crush the UN forces at Pusan before the Americans could carry out the operation. Within 10 days of the landings, the Marines recaptured Seoul.

At Pusan, the reinforced UN forces launched their own offensive on Sept. 16 and within days were driving the North Koreans back. Trapped between two surging enemy armies, the already-weakened North Korean forces disintegrated with astonishing speed. Fewer than 40,000 stragglers made their way, without equipment, back to North Korea. For the U.S.-led coalition, the war seemed all but won.

The rapidity of the communist collapse made total victory and even the reunification of the two Koreas under the political leadership of Seoul suddenly seem possible. Even amid dire warnings from Beijing not to invade the North, the Joint Chiefs and President Truman gave MacArthur the go-ahead to push above the 38^th Parallel.

But China wasn’t bluffing. As MacArthur’s headed north and on towards the Yalu River, the army of the People’s Republic prepared to enter the war. By late October, ROK patrols had reached within a few miles of Chinese border. Then on Nov. 25, a quarter-million Chinese troops attacked the Allied lines driving the U.S. and ROK back again. What was left of Seoul was recaptured by the communists.

By early 1951, UN resistance stiffened and front soon stabilized roughly along the old pre-war border. Both sides settled in for a bloody two-year stalemate that was finally ended by an armistice in 1953.

ABOUT THE AUTHOR: Walter Topp is a former U.S. Navy officer, emergency manager, police officer, and newspaper reporter. He is currently a writer and is working on several history and emergency management projects. He speaks regularly on emergency management topics but prefers writing about military history. He is a regular contributor to MilitaryHistoryNow.com.