A national security expert noted that special counsel Robert Mueller is the least of Donald Trump’s problems — and that he’s likely much more worried about Vladimir Putin.

In an op-ed for the Observer newspaper, former National Security Agency analyst John R. Schindler wrote that the Trump Organization showed off its “stunning ineptitude” with its reported discussions to give Putin the $50 million penthouse in the scrapped Trump Tower Moscow project.

“Trump’s representatives reached out to senior Russian government officials, not just private businesspeople,” Schindler wrote. “They seem never to have realized that the line between Kremlin bigwigs, Russian spies, and organized crime players, never thick in Moscow, has been erased entirely during two decades of Putin’s rule.”

The plea deal between Trump’s former “fixer” Michael Cohen and Mueller is, the counterterrorism expert noted, the first legal corroboration of the relationship between the president and Putin — but the latter’s anger is much more dangerous to him than Mueller closing in.

“The Kremlin’s displeasure with its erstwhile friend, rising for months, has risen to hazardous levels for the White House,” Schindler noted. “The breaking point is Ukraine. Last weekend, Putin’s Federal Security Service engineered an armed confrontation in the Black Sea, grabbing two Ukrainian navy patrol boats and their crews as booty.”

After issuing a “timid” response to the Kremlin’s incursion in Ukraine, Trump then had the gall to cancel via tweet his planned meeting with Putin — ostensibly because of “the fact that the ships and sailors have not been returned to Ukraine from Russia.”

Moscow was “furious” at the response, the security expert noted.

“We regret the decision of the U.S. administration to cancel the scheduled meeting of the two presidents in Buenos Aires,” Kremlin spokesperson Dmitri Peskov said. The move, he added, “means that discussion of serious issues on the international and bilateral agenda is being postponed indefinitely.”

“In other words: you don’t get to cancel meetings, we do—and if you think the Kremlin will help you out, Don, have we got news for you,” Schindler translated.