Operation Chromite

History

MacArthur first envisioned a landing at Inchon code-named Operation Bluehearts for 22 July 1950, but that plan was abandoned by 10 July, and on 23 July he gave the codename Operation Chromite to a new plan calling for an assault by the 2nd Infantry Division and the 5th Marine Regiment. That plan was revised again and the 7th Infantry Division was chosen as the landing force; MacArthur activated US X Corps and appointed Major General Edward Almond as its commander. Through August he re-equipped the 7th Infantry Division, rebuilt the 1st Marine Division, and allocated incoming equipment to X Corps.

The initial plan met skepticism: Inchon's approaches were restricted and minable, currents ran 3–8 knots, and the tides were extreme. US Navy leaders favored a landing at Kunsan, closer to the Pusan Perimeter, but MacArthur argued that a Kunsan landing would not produce a decisive victory and would not surprise the Korean People's Army. At the 23 August 1950 Tokyo meeting he won over CNO Admiral Forrest Sherman and Army Chief of Staff J. Lawton Collins; the Joint Chiefs of Staff approved the plan on 28 August and President Truman also gave his approval.

Vice Admiral Arthur Dewey Struble's Joint Task Force 7 included fast carrier, Royal Navy, and attack task force groups. Wolmi-Do was the tactical key to Inchon, to be taken by a separate morning-tide landing before the main evening landings. Naval and air bombardment began on 13 September, and on 15 September the 1st Marine Division assaulted three beaches and secured Inchon. By 19 September the Marines had captured Kimpo air base, US Army troops advanced from the beachhead and linked up with forces moving north from the Pusan Perimeter, and on 28 September Marine, Army and South Korean troops recaptured Seoul.

To protect the surprise, UN forces staged an elaborate deception to make it appear the landing would take place 105 miles south at Kunsan: Far East Air Forces raids on roads and bridges from 5 September, a naval bombardment of Kunsan on 6 September, B-29 raids from 11 September, and a 12–13 September Royal Navy landing of special operations troops and Royal Marine Commandos at Kunsan. A spy ring leader arrested in Japan in early September 1950 had a copy of the Operation Chromite plan, and the UN did not know whether it had been transmitted.

The US Navy's assessment stresses that the success depended on a strong and coordinated sea, air, and land force, and that the invasion demonstrated how naval forces can be a decisive factor in littoral operations. Korean-language material contains errors, including a 13 September start date and an invented UN commander; these conflict with the same material's own 15–19 September dating and with MacArthur's documented command, so they are not adopted here.

Distinctions

"Operation Chromite" is the codename for the landing operation itself, while the wider action is also recorded as the Battle of Inchon. It is distinct from later operations at the same place or region, including the Second Battle of Inchon and the Wonsan landing.

As candidate landing sites, Inchon and Kunsan served different strategic purposes. US Navy leaders favored Kunsan, nearer the Pusan Perimeter and the KPA main supply axis, but MacArthur judged a Kunsan landing "would be an attempted envelopment that would not envelop" and would place more troops in a vulnerable pocket of the Pusan Perimeter, so he chose Inchon against the Navy's preference.

The Inchon landing was also not the first large-scale amphibious operation since World War II; that distinction belonged to the UN landing at Pohang on 18 July 1950, which was not made in KPA-held territory and was unopposed. The abandoned 22 July 1950 Bluehearts plan is distinct from the 23 July 1950 Chromite plan, whose name and force composition were superseded again when those units went to the Pusan Perimeter.

Examples

Concrete instances of the diversionary campaign are the 5 September 1950 Far East Air Forces attacks on roads and bridges to isolate Kunsan, the naval bombardment of Kunsan on 6 September, and the 11 September USAF B-29 bombing of military installations in the area.

Before the landing, Wolmi-Do was bombed and shelled twice, and from 17 August to 14 September a Republic of Korea Navy intelligence unit carried out Operation X-ray, lighting the Palmi-do lighthouse beacon at 00:50 on 15 September. On 16 September, the day after the initial landings, four LSTs unloaded men and equipment while high and dry at low tide on Inchon's Red Beach, illustrating the extreme tidal conditions of the target.