It’s all hail-fellow-well-met in public between Donald Trump and Kim Jong-un, but below the surface it’s business as usual. NBC reports this morning that North Korea has continued to produce nuclear warheads over the last few months despite Kim’s claims of having ended the program unilaterally. The White House has taken steps to get tougher with Kim as well, despite Trump’s public embrace of the hereditary dictator:

As President Donald Trump issues a steady stream of praise for Kim Jong Un in interviews and on Twitter, a steady stream of evidence that North Korea is still making nuclear weapons has pushed his administration to take a much more aggressive stance toward Pyongyang.

The newest intelligence shows Kim’s regime has escalated efforts to conceal its nuclear activity, according to three senior U.S. officials. During the three months since the historic Singapore summit and Trump’s proclamation that North Korea intends to denuclearize, North Korea has built structures to obscure the entrance to at least one warhead storage facility, according to the officials.

The U.S. has also observed North Korean workers moving warheads out of the facility, the officials said, though they would not speculate on where the warheads went.

Kim has certainly tried selling his posturing as substantial, and at times it seems to have worked. Trump responded favorably to Kim’s decision to leave ICBMs out of his military parade this weekend, calling it “a very positive statement” on Twitter. That got a lot of notice from the media:

North Korea rids missiles from military parade. CNN's Will Ripley reports live from Pyongyang. @earlystart @willripleyCNN pic.twitter.com/gc82SjXKP7

— CNN Early Start (@EarlyStart) September 10, 2018

https://twitter.com/realDonaldTrump/status/1038812262549663744

That may seem a little naïve, but NBC reports that it’s mostly for public consumption. Behind the scenes, Trump is running the maximum-pressure campaign that intends to get Kim to back down, according to NBC’s sources. It’s about to go to another level:

The first sign of the shift will be at sea, officials said, where an international maritime coalition will step up its efforts to expose ships and nations that are evading sanctions with illegal transfers of goods between ships at sea, according to three senior U.S. officials. …

The international coalition, which includes military ships from the U.S., UK, France, Australia, New Zealand, Japan, and South Korea, has already been patrolling the waters for several months, but there is now an effort to “go active,” according to one senior US official, meaning the coalition would begin to publicly denounce individuals who violate the sanctions at sea.

Japan had already announced that it would step up its efforts to interdict sanctions-violating maritime activity, which it would hardly do without US support. So which is the story here — “dialogue between two people who like each other,” or a toughening standoff? It could very well be both, actually. Trump is lavishing praise on Kim as a manipulation (as Kim is with Trump) while turning up the heat to force Kim into denuclearization. This way Kim has room to claim that it’s his idea.

However, Kim has other ideas. Russian parliamentary leader Valentina Matvienko told the Russian press that Kim wants the US to make concessions for the moves he’s already made, and is puzzled that we haven’t made any yet:

A senior Russian official who met Kim Jong Un this weekend cited the North Korean leader as saying he did not plan any unilateral steps to denuclearize and was instead awaiting a U.S. response to steps he already took, Russia’s RIA news agency reported. …

Matvienko said Kim Jong Un had been polite and diplomatic in his remarks about U.S. President Donald Trump, RIA reported. She also quoted him as saying he hoped for Russian backing in weakening U.S. sanctions on North Korea.

That was the pattern established by Kim’s father, Kim Jong-il — make a few public-relations moves and wait for the US to pony up food, aid, and a relaxation on sanctions. Trump and Mike Pence warned that we wouldn’t follow that old pattern, but Kim had to at least try to see if that strategy still worked. Trump needs to hold firm against that old dodge and force Kim into real, verifiable concessions first.