Last week, President Trump tweeted that he was canceling sanctions announced by the U.S. Treasury Department against North Korea. For hours after that announcement, it was still unclear just what the president was talking about. Eventually, the official explanation given was that Trump had been referencing yet-to-be-announced sanctions.

This week, however, Bloomberg News reported that that official explanation had been a cover-up. Instead of talking about unannounced sanctions, Trump had been referencing already-announced penalties against two Chinese shipping companies that had worked with Pyongyang in violation of U.S. sanctions.

It now appears that Trump’s dislike for the sanctions against the shipping firms had little to do with North Korean dictator Kim Jong Un and everything to do with China.

As the Trump administration and Chinese counterparts try to hammer out a trade deal to end tariffs that are hurting economies on both sides of the Pacific, it would make sense if Trump viewed these sanctions targeting Chinese firms as bad for a trade deal.

That reasoning would also be in line with previous decisions to back off penalties for Chinese companies in favor of fostering a better relationships and a trade deal. Indeed, in 2018, Trump made a similar move with Chinese phone company ZTE. After the company was caught violating international sanctions against Iran, the U.S. imposed stiff penalties and raised new security concerns. Trump, however, reversed course announcing that he wanted to work with Chinese President Xi Jinping to help ZTE out:

President Xi of China, and I, are working together to give massive Chinese phone company, ZTE, a way to get back into business, fast. Too many jobs in China lost. Commerce Department has been instructed to get it done! — Donald J. Trump (@realDonaldTrump) May 13, 2018

Similarly, Trump has floated the idea that Huawei executive Meng Wanzhou might get off the hook for violating Iran sanctions as part of a trade deal.

Of course, there are several problems with this apparent strategy of wooing China by giving Chinese companies a pass for breaking sanctions.

First, it sends the message that the U.S. doesn’t take its sanctions seriously as law enforcement actions. Instead, as Trump’s “make a deal” approach suggests, they are bargaining chips to be bought or sold with trade deals.

Additionally, it undermines the entire basis of claimed adherence to the rule of law. If sanctions can be placed or lifted simply on presidential whim, that strongly implies that they were initially placed not based on evidence or real concerns of wrongdoing, but simply to further U.S. economic interests abroad.

All of that undercuts a key aspect of sanctions: international adherence. U.S. sanctions are powerful not only because of the strength of the U.S. economy, but because of our ability to unite our allies and compel compliance with sanctions Washington deems necessary. That only works if other countries see those sanctions as legitimate law enforcement actions based on shared concerns. By instead treating sanctions as tools to achieve a trade deal, the U.S. will lose much-needed international support for future sanctions.

[Read more: US Forces Korea commander: North Korean activity ‘inconsistent with denuclearization’]