Late in the afternoon on Tuesday, President Trump waded into the controversial arrest of Huawei executive Meng Wanzhou. In an interview with Reuters at the White House, Trump said that her release could be part of a broader trade deal with China.

That’s a loaded statement that implies Trump sees her arrest not as a legal matter, as U.S. and Canadian authorities have claimed, but as a political bargaining chip — a human hostage for a better deal.

Meng, the chief financial officer of the telecommunications giant, was arrested by Canadian officials at the Vancouver airport at the request of the U.S. Justice Department. She faces charges for allegedly misleading multinational banks about Huawei’s Iran-linked transactions, in violation of U.S. sanctions.

On Tuesday, a Canadian judge granted bail to Meng, allowing her to live at her family’s home in Vancouver while wearing an ankle monitor. To make her bail, set at $7.5 million, five of her friends pledged equity in their homes and other assets.

The case against her is before Canadian courts. If it is ruled to be strong enough, she would likely be extradited to the United States to face charges, although the ultimate decision on extradition falls to Canada’s justice minister.

By opening the possibility of presidential intervention, Trump undercuts that legal process. He also undermines both U.S. and Canadian officials, who have repeatedly asserted that the arrest was not politically motivated.

For Beijing, which has long alleged that the enforcement of U.S. laws is political rather than based on legal reasoning, Trump's admission is a clear win.

Worse, that admission lends justification to Chinese authorities arresting a Canadian citizen for alleged violations of Chinese law on Tuesday. That move was widely understood as a retaliation against Canada.

But the complications extend beyond the current spat, lending justifications to other actions by Beijing. Earlier this fall, for example, two U.S. citizens, the children of a former Chinese official charged with corruption, were banned from exiting China and have not yet been allowed to return the U.S.

Since the issuing of exit bans, national security adviser John Bolton has criticized China’s tactics of holding citizens as political hostages but has made little effort to the resolve the situation. Now, if the U.S. is engaging in similar tactics, as admitted by none other than the sitting president, that leaves Washington with little legal or moral credibility.

Although many in the U.S. are happy to dismiss Trump’s comments as “just rhetoric,” they are taken as policy abroad. Here, Trump has undercut a DOJ investigation into Iran sanctions violations and lent legitimacy to politically motivated detentions abroad. This is why the law should not be enforced merely as a tool of presidential whim.