Editor's note: Michael Dolski is a historian with the Defense Department's POW/MIA Accounting Agency. The department requires that he submit material such as this for review. This article was submitted but no substantive changes were made in the piece.

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Ushered from the two Air Force cargo planes on Aug. 1, the 55 flag-draped transfer cases had officially come "home." The repatriation ceremony held last week at Joint Base Pearl Harbor-Hickam on Oahu, Hawaii, was only the latest chapter in the long saga of U.S.-North Korea negotiations over peace and security on the Korean Peninsula.

In many ways, the homecoming was more symbolic than material. Despite the fanfare, a great deal of forensic work will be needed to identify the individual sets of remains. Years may pass before fallen service members are returned to surviving relatives. Some may never be identified.

Such delays and uncertainty may challenge Americans' expectations about how the U.S. accounts for its missing service members. But they also tell us something about the conditions of the war — and about the limitations of the forensic science of identifying war dead decades later.

The U.S. has a unique tradition of caring for its fallen — specifically, the belief that each service member deserves the full attention of this vast accounting enterprise and that every family deserves the opportunity to decide where that person should be interred and, thus, honored. No other country goes to such lengths and expends such resources to account for its missing. It's a tradition that the Korean War has carried on, but also transformed.

Why should we expect the potential delay? For starters, it's not certain that the remains are exclusively American. Initial reviews carried out by scientists from the Defense POW/MIA Accounting Agency (DPAA) are encouraging, but getting definitive answers will take time. Though the United States contributed 90 percent of the military personnel to the United Nations' forces during the Korean conflict from 1950 to 1953, hundreds of thousands of South Korean, North Korean, Chinese and other nations' troops also died during the war.

Part of the problem lies with not knowing where these troops died, or if their bodies were temporarily buried and subsequently relocated. It's unclear why North Korean officials decided to turn over only 55 sets of remains after originally pledging to hand over 200. Also unclear is the "provenance" (meaning the original recovery location) of these presumed American remains.

As a result, the forensic scientists at DPAA may have little context for their work. Not knowing where the remains were originally recovered means they can't narrow the geographic scope of inquiry and so they can't exclude significant numbers of potential fallen. Another possible problem is that the contents of the 55 transfer cases may not add up to 55 individual service members; those numbers haven't always matched, in the past. For example, in the early 1990s, North Korea handed over 208 boxes of "individual" remains. The 208 cases turned out to represent approximately 600 individuals whose bones were commingled, including those of at least 12 Korean nationals. The lab's scientists are still working to identify those remains more than two decades later.

DNA is likely to prove a critical tool in identifying these remains, but this testing doesn't come with a guarantee. DNA testing can identify a missing person only if the bone sample's genetic profile can be compared against DNA sequences collected from blood relatives. Since the early 1990s, the Armed Forces DNA Identification Laboratory (AFDIL) has collected "family reference samples" from Korean War families. They have approximately 90 percent of the needed family DNA profiles on file.

The remains themselves have to yield DNA to arrive at matches. They do 92 percent of the time, but, in some cases, they may be too degraded to produce viable results. Even if things go well — if the bones yield usable DNA and matches can be made — there may be extensive commingling. The scientists at DPAA may have to cut and send multiple bone samples from the same skeleton to AFDIL for DNA testing. In such cases, DNA evidence augments forensic anthropological and dental analysis in sorting and identifying remains. But such a process may take years and require significant resources.

Since the Civil War, the U.S. has had a tradition of identifying the bodies of the fallen and sending them home to surviving kin. For most service members' families from World War I onward, that meant that the remains of their fallen were returned to U.S. soil, not buried on the battlefield where they fell. For example, in World War II, though the U.S. created 14 national military cemeteries abroad, more than 65 percent of families chose to have their fallen repatriated, and the government spent millions of dollars in the effort. That's not the approach of most other nations, including many European and Commonwealth nations.

But the U.S. took an even more ambitious approach during its Korean War. For the first time in its military history, it adopted a policy of "concurrent return," repatriating remains while the war was still being waged. Historian Kurt Piehler has argued that the shift came because the U.S. wasn't confident about the war's outcome and "whether future access to a U.S. military cemetery in the Republic of Korea could be guaranteed." By the end of the war, U.S. officials sought the repatriation and identification of all their fallen.

During the official war-dead negotiations, both the U.S. and North Korea made clear that they sought similar ends: to obliterate many of the traces of the war. For the North Koreans, removing the remains of the foreign interlopers proved one way to cleanse their homeland. The Americans, for their part, sought to bring their fallen service members safely home. These shared goals helped the negotiations succeed. They also paved the way for the repatriation earlier this month.

Michael Dolski is a historian with the Defense Department's POW/MIA Accounting Agency. Sarah Wagner is an associate professor of anthropology at George Washington University. They wrote this article for The Monkey Cage, an independent blog hosted by the Washington Post and anchored by a group of political scientists from universities around the country. (See www.washingtonpost.com/blogs/monkey-cage). The views presented here are those of the authors and do not necessarily represent the views of the Department of Defense or its components.