If Donald Trump disclosed highly classified state secrets to the Russian ambassador and foreign minister, he may be vulnerable to impeachment — not because he broke the law, which evidently he did not, but because he committed an act that would be considered criminal and perhaps treasonous if perpetrated willfully by any other government official.

Trump is exempt from the criminal statutes governing disclosure of classified information because he can legally declassify anything at will. But whimsical and boastful misuse of that authority, in the presence of an adversary power, is an extremely serious offense that requires immediate Congressional investigation.

The president has put the nation at risk, not for the first time, and his apparent disdain for normal security and intelligence protocols represents an ongoing national emergency. It is an emergency that began within weeks of his inauguration, when he and his staff formulated their response to a February 12 North Korean missile test as diners at his Mar-a-Lago club watched agog from surrounding tables.

In the hours after the Washington Post revealed this latest breach — which involved information about a terrorist plot by the Islamic State — Trump’s national security adviser H.R. McMaster publicly declared that “the story, as reported is false.” McMaster went on to deny specifically that the president had discussed “intelligence sources or methods” or “any military operations that were not already publicly known.”

But McMaster’s statement is a non-denial denial, to recall a Watergate phrase, which doesn’t respond to what the Post reported and other news outlets have since confirmed: Namely that the president told the Russians about the ISIS plot and the city in which it originated.

Undoubtedly the Russian intelligence services (and their allies in Tehran and Damascus) will seek to trace the identity of the US sources, using the data Trump allegedly disclosed. And the allied intelligence service and human assets who provided that vital information, which is essential to protect the United States, will either be compromised or reluctant to work with our services in the future — because the president of the United States endangered them to puff himself up.

There is a simple way to see whether Trump disclosed classified information to the Russians: Check the official transcript of their meeting. Every time an American president meets or speaks with a foreign official, their conversation is either recorded digitally or transcribed by a “rapporteur,” usually an official on the National Security Council staff — every single word.

As a rule, those transcripts are closely held and likely protected by executive privilege. But there is also a clear precedent to provide such a transcript to Congress for investigative purposes. In 2001, while investigating President Bill Clinton’s last-minute pardon of the indicted fugitive Marc Rich, the House Oversight Committee asked the Bush White House for transcripts of three telephone conversations about Rich between Clinton and Ehud Barak, then the prime minister of Israel. President Bush ordered those transcripts to be released immediately (and their content indicated an innocent explanation for the pardon, but that’s a different story).

Now the House and Senate intelligence committees should request — or if necessary, subpoena — the transcripts of Trump’s meeting with the Russians, to see who is telling the truth. To paraphrase Trump, that may be the only way to “find out what the hell is going on.”

Until we find out what is going on in the White House, it is too soon say whether there are grounds to impeach the president over this reported betrayal of secret intelligence, his obvious unfitness for office, or his admitted effort to curtail a federal counter-intelligence investigation of his presidential campaign’s alleged collusion with the Kremlin (by firing FBI director James Comey the day before his Oval Office meeting with the Russian diplomats).

But bear in mind that Congress can impeach whether or not the president has committed a statutory felony. Many scholars agree that the definition of “high crimes and misdemeanors” is political rather than juridical, and that under the Constitution, impeachable offenses are determined solely by a majority vote of the House of Representatives. They also agree that the intent of the impeachment clause is to punish abuses of power and to remove officials who are unfit to serve.

This is not a partisan issue. Only Congress, Republicans and Democrats acting together, can protect the nation from this incompetent, venal, and dangerous executive. They can no longer ignore the threat he poses to our security.

IMAGE: A combination of file photos showing Russian Foreign Minister Sergei Lavrov attending a news conference in Moscow, November 18, 2015, and President Donald Trump posing for a photo in New York City, May 17, 2016. REUTERS/Maxim Zmeyev/Lucas Jackson/File Photos