SEOUL—The North Koreans are drawing everyone from President Donald Trump to the U.S. military command here into excited expectation Kim Jong Un is about to return the remains of a few U.S. soldiers from among the 5,300 still listed as “missing in action” 65 years after the Korean War. But there’s something lost in the exaltation: talk of “complete denuclearization.”

When Trump told a rally in Duluth, Minnesota, last week that North Korea already had returned the remains of 200 of “our great fallen heroes,” U.S. and South Korean officials were puzzled, to say the least. Nobody here had heard about the return of the remains since Trump had taken credit for getting Kim to agree to a fourth point on the slim statement they signed at the Singapore summit on June 12: “The United States and the DPRK commit to recovering POW/MIA remains, including the immediate repatriation of those already identified.”

Since then, the North Koreans have conducted a dilatory process leading at last to an understanding by the U.S. command that the Kim regime is poised to return maybe 200 remains, maybe more, maybe less.

Clearly something’s up. U.S. Army trucks carrying 100 wooden coffins have moved to the joint security area straddling the line between the two Koreas at the truce village of Panmunjom. The trucks have unloaded trestles on which the coffins are resting, and flags of the United Nations Command, which includes the U.S. and 16 Korean War allies, are flying above them.

That doesn’t mean that anyone knows for sure what’s happening. Even Defense Secretary Jim Mattis seemed uncertain on his way to the region this week. The U.N. Command “is prepared now to receive those remains,” he said. “We are simply standing by for whatever diplomatic activities are done.” He was “optimistic,” he said, since “that was an agreement coming out of Singapore”—a reference, that is, to transfer of the remains, not the nuclear issue. Mattis arrives Thursday in Korea on a swing that’s also taking him to China and Japan.

While the Americans wait for the North Koreans to produce the remains, North Korea’s state media have said nothing about them, much less about denuclearization. Rather, a North Korean website promised to “fulfill our responsibility to address decades-long tensions and hostile relations and open a new era of the North-U.S. cooperation.” The same website called for abolition of South Korea’s “North Korean human rights act,” scolding South Korean officials for ignoring “shifting circumstances and public sentiment.”

“ To [the North Koreans] the remains are nothing. They are using them. ” — Political Analyst Shim Jae-hoon

For longtime observers of North Korean negotiating techniques, North Korea’s basic strategy is plain.

“The North Koreans are trying to feed unimportant crumbs instead of focusing on weighty issues like denuclearization,” said Shim Jae-hoon, a political analyst who wrote for years for the old Far Eastern Economic Review. “They avoid making concessions on serious matters. To them the remains are nothing. They are using them. The whole North Korean approach is to be protracted.”

In fact, U.S. officials are preparing now for a full-dress ceremony complete with honor guard at the crossing in Panmunjom, and they are gearing up for a still larger show at Osan Air Base 40 miles south of Seoul. They wonder, however, how as many as 200 sets of remains can be handed over at one time—or if they’ll be returned in batches over an extended period.

Consider the history: In an exercise called Operation Glory in 1954, in accordance with the Korean War Armistice signed in July 1953, the North Koreans transferred a total of about 3,000 bodies. Over a four-year period from 1990 to 1994, they handed over 200 boxes of remains. From 1996 to 2005 U.S. experts visited battlefields on 33 “joint field activities” with North Koreans, recovering 220 sets of remains.

But what if the North Koreans were to take those American experts hostage as tensions worsened after the North withdrew from the nuclear non-proliferation agreement in 2003 in the run-up to its first nuclear test three years later? Amid such worries, the U.S. in 2005 suspended searches. The North Koreans have returned no remains since 2007 while nuclear and missile tests fueled fears of a second Korean War—until Kim switched tactics and opened his peace offensive early this year.

Even in the best of times, transfers have generally been one or two at a time. If all 200 sets of remains were returned at once, as Trump said had already happened, he would not be far off in applying some of his favorite adjectives—amazing or terrific or even unprecedented, at least since 1954.

However many are turned over at one time, over how long a period, the remains will be transferred at Osan to aluminum caskets before they’re loaded onto transport planes and flown to Hickam Air Force Base in Hawaii for forensic examination under the U.S. Defense POW-MIA Accounting Agency. The initial challenge will be to determine which remains are those of Americans, which of allied soldiers, and which are Korean—a task made that much more difficult by the fact that the North Koreans are believed to have been holding them in storage for years.

Experts from the Defense POW-MIA Accounting Agency reportedly have been to Korea attempting firm up arrangements even as the North Koreans work the return to maximum propaganda advantage. And even if the prospect of returning remains represents, in Trump’s roseate view, a step toward permanent peace, U.S. experts doubt the North Koreans will permit American search teams to scour battlegrounds as they did before 2005.

“ There is no substitute for having American experts in this field directly engaged. ” — Evans Revere, former deputy chief of mission, U.S. Embassy, Seoul

“I am concerned that the agreement does not seem to have included the requirement to have U.S. remains recovery experts on the ground inside North Korea,” said Evans Revere, former deputy chief of mission at the U.S. embassy here. “There is no substitute for having American experts in this field directly engaged.”

Even if American teams do enter North Korea accompanied by North Korean forces the results are likely to be very disappointing—and expensive. “The North Koreans will exploit this as they did before and slow-roll it to get guys over there looking through old battlefields and then over-charge on every single little cost,” said Bruce Bechtol, a former U.S. defense intelligence official and author of numerous studies on North Korean military issues. “This is something that could probably be completed in months, but of course the North Koreans will drag it on for years.”

Stephen Tharp, a retired U.S. army officer who attended numerous meetings at the Joint Security Area, including ceremonies for the return of remains, sees the North Koreans as essentially following a familiar routine with no really satisfactory results.

“The way that North Korea can return 200 sets of remains so quickly is that they’ve been stored in warehouses for decades,” said Tharp. “It takes about five seconds for an anthropologist to see the bones have dried out and become cured.”

In one case 25 years ago, Tharp recalls, “They found catalog markings etched on them.”

Of course none of that will keep Trump from describing the return of remains as a great success for his negotiating techniques while, amid the blaze of publicity, that goal of “complete denuclearization” fades into the dim background.