United Nations The Battle of Triangle Hill, also known as Operation Showdown or the Shangganling Campaign (Chinese: 上甘岭战役; pinyin: Shànggānlǐng Zhànyì),[nb 3] was a protracted military engagement during the Korean War.

Over the course of nearly a month, substantial US and Republic of Korea Army (ROK) forces made repeated attempts to capture Triangle Hill and the adjacent Sniper Ridge.

Despite clear superiority in artillery and aircraft, the escalating UN casualties resulted in the attack being halted after 42 days of fighting, with PVA forces regaining their original positions.

[18] General James Van Fleet commander of the Eighth US Army had hoped that the change of commanders would allow him to reengage the PVA in a major campaign,[19] but in an effort to limit UN losses during the peace talks in Panmunjom, Clark repeatedly overruled Van Fleet's requests for an authorized offensive into North Korean territory.

[20] In September 1952, the negotiations at Panmunjom began to deteriorate, primarily due to Sino-North Korean insistence that all prisoners of war be repatriated to their respective original countries, regardless of their preferences.

[17] Feeling that the negotiations would soon fail, military commanders on both sides authorized numerous tactical plans as means of applying pressure on their opponents.

[22] In late September, the PVA High Command authorized the tactical plans which led to the Battle of White Horse Hill.

UN planners expected the operation to last no more than five days with 200 casualties on the UN side, based on the assumption that maximum artillery and air support would be available.

[28] Qin Jiwei,[nb 4] commander of the 15th Corps, predicted that any major American attack would be one of mechanized infantry and armor directed at the Pyonggang Valley 20 km (12 mi) to the west of Triangle Hill.

[31] On 5 October 1952, a staff officer of the ROK 2nd Infantry Division defected to the PVA, bringing with him a complete battle plan of Operation Showdown, but the information was not taken seriously by the Chinese.

[32] At 04:00 on 14 October 1952, following two days of preliminary air strikes,[25] the ROK-American bombardment intensified across the 30 km (19 mi) front held by the PVA 15th Corps.

[33] The concentrated bombardment succeeded in clearing the foliage on Triangle Hill and Sniper Ridge, destroying most of the above-ground fortifications on the two positions.

When only partial progress could be claimed by the late afternoon, US and ROK attacks subsided and preparation of defensive positions to face a PVA counterattack began.

[59] Despite the initial setbacks, Deng Hua, acting commander of the PVA, considered the situation a golden opportunity to bleed the US military white.

[61] Van Fleet decided to rest the US 7th Infantry Division on 25 October, thus sidestepping the PVA intention of inflicting additional casualties on the Americans.

[68] Before the start of the battle, Qin Jiwei had worried that Van Fleet would try to lure the PVA forces around Triangle Hill, with the real blow directed towards the Pyonggang Valley.

[71] At noon on 30 October, the 15th Corps bombarded the ROK with 133 large-caliber guns, 22 rocket launchers and 30 120 mm heavy mortars in the largest Chinese artillery operation of the war.

[62][nb 5] Although the ROK failed to recapture the hill, the resulting heavy casualties forced the PVA to call in the 93rd Regiment, 31st Division as reinforcement on 5 November.

[76] On the same day, Lieutenant General Reuben E. Jenkins, commander of US IX Corps, suspended further attacks on Triangle Hill to prevent more casualties and to protect Sniper Ridge.

[13] The high numbers of UN casualties and pressure from Clark made Van Fleet break off Operation Showdown on 28 November and thus end the Battle of Triangle Hill.

[85] For the PVA, on the other hand, not only did the 15th Corps stop the UN attacks at Triangle Hill, the assaults conducted by the 44th Division on the Pyonggang front also resulted in Jackson Heights' capture on 30 November.

[87] As for the ROK, the modest UN gain on Sniper Ridge had convinced them that they were now capable of conducting independent offensive operations, even though the American advisers were less than impressed with their performance during the course of the battle.

[11] The courage demonstrated by the PVA soldiers at Triangle Hill was repeatedly glorified in various forms of media, including several major motion pictures.

[91] Qin Jiwei was also celebrated as the hero of Shangganling and eventually rose to become the Minister of Defense and the Vice Chairman of the National People's Congress.