SEOUL—Atop a little-known ridge almost seven decades ago, French, South Korean and American troops fought off waves of mainly Chinese Communist forces in a series of trench battles that marked some of the bloodiest days of the Korean War.
Hundreds of the fallen were never recovered from Arrowhead Hill and adjacent peaks; their remains lie in no-man’s-land inside the demilitarized zone that separates North and South Korea.
Now, warming inter-Korean relations have fostered a joint effort to retrieve the remains of some 300 United Nations soldiers and perhaps thousands of Chinese. The project shows how the two Koreas are extending their cooperation even with sanctions in place on Pyongyang and in the absence of concrete North Korean steps to denuclearize.
Both sides have removed land mines from the area and built a road to provide access for excavation scheduled to begin April 1. South Korean soldiers plan to carefully reclaim the remains from sites where earlier investigations have uncovered artifacts such as dog tags.
“Everyone there will be using their bare hands,” said Maj. Kim Dae-su, a spokesman for the South Korean military unit that specializes in searching for war remains.
Identifying remains is a laborious task. The soldiers—including some who trained as archaeologists—gather the bones and battlefield evidence before specialists in a laboratory compare them to DNA samples provided by relatives. The process can take years, and the presence of many nationalities in the battle complicates the process.
To expedite the identification work, Seoul defense officials said they have reached out to the U.S. and other countries to supply them with relevant DNA samples, which they hope will allow for preliminary DNA matching at the excavation site.
South Korean officials say they chose Arrowhead Hill for the excavation because soldiers from many countries fought there. If a soldier from one country is found, the two Koreas would have reason to invite that country to join in the excavation effort—injecting momentum into the detente on the peninsula. Searchers have already found 13 bodies during the demining process, most of which were thought to be South Korean, Maj. Kim said.
For North Korean leader Kim Jong Un, who is preparing for a second summit later this month with President Trump, the effort fits into a charm offensive aimed at improving relations with South Korea and China. In a Jan. 1 speech, Mr. Kim said Seoul should cease military exercises with Washington and proceed with inter-Korean economic projects, despite sanctions that restrict investment in North Korea.
The two Koreas’ bilateral effort to recover the war remains serves Pyongyang’s goals, said Jiyul Kim, a retired U.S. Army intelligence officer and a professor of history at Oberlin College in Ohio. “It humanizes North Korea,” he said, without contributing to the nuclear talks.
Others see the excavations as a goodwill gesture from Pyongyang that could facilitate better ties with the U.S. “The North Koreans know that Western countries like the U.S. and France value recovering their war dead,” said Choi Kang, the vice president of the Asan Institute for Policy Studies, a private think tank in Seoul.
North Korea returned 55 sets of remains to the U.S. last year following the June summit between Messrs. Trump and Kim in Singapore. Three sets of remains have since been identified. U.S. Special Envoy Stephen Biegun said last month that the most recent identification was Sgt. Frank Julius Suliman.
Beyond remains, the new excavation project—the product of an inter-Korean summit in September—could also reveal insights into the battles at Arrowhead, also known as Hill 281.
The ridge and its surrounding peaks changed hands dozens of times during the three-year conflict. Soldiers there endured grueling trench warfare and hand-to-hand combat that one French survivor likened to the fighting at Verdun, the World War I battle in northeastern France.
Chinese forces greatly outnumbered allied defenders at Arrowhead Hill. “Compared to the 54 Frenchmen, they had the numerical advantage of a Xerxes invading Greece at Thermopylae,” according to a March 1953 report by Andrew Headland Jr. in Stars and Stripes, the main U.S. military newspaper, in an article discussing an engagement a few months earlier.
Mr. Kim, the Oberlin College expert, said he doubted that the excavations in the area would result in the discovery of missing Americans, saying the most-intense fighting there involved Korean, Chinese and French forces.
The Pentagon’s Defense POW/MIA Accounting Agency, the federal bureau charged with recovering American war dead, didn’t respond to requests for comment. But the agency has said previously that it suspects 1,000 missing GIs could be resting in the demilitarized zone that bisects the Korean Peninsula. Arrowhead Hill is roughly in the middle of the 160-mile strip.
If remains recovered from the battlefield are found to be those of an American or French serviceman, they will be sent to the relevant country, likely after a proper ceremony, said Maj. Kim, the spokesman for the South Korean military unit involved in the process.
“Usually, diggers are able to make an educated guess on whether the remains belong to those of European descent or Asian descent,” he said.
While wider geopolitical events loom over the excavations, the project marks another step in rejuvenated ties between North and South Korea. Among their agreements over the past year was a pledge to withdraw front-line guard posts in the DMZ.
One of those guard posts is on Arrowhead Hill, according to South Korean defense officials, just a few hundred feet from where South Korean excavators will search for the war dead.
Write to Andrew Jeong at email@example.com