There were at least six topics that Donald Trump could have forcefully raised with Russia’s Vladimir Putin at Monday’s so-called summit in Helsinki, Finland. Any other president would have.

First was Russian meddling in the 2016 presidential election.

Second was Russia’s presence in Syria.

Third was the unlawful Russian annexation of Crimea.

Fourth was Russia’s intrusion into eastern Ukraine.

Fifth was Russia’s continued and ominous expressions of “concern” for Russian speakers in the Baltic states, particularly Latvia and Estonia, that echo some of the rhetoric prior to Putin’s actions in Ukraine.

Sixth was Russia’s possible help to North Korea given Putin, after all, was reportedly the one who suggested Trump scrap joint U.S.-South Korea military exercises.

But it’s the first lost opportunity that was most astonishing. Trump didn’t criticize the Russians. Instead, he backed Putin’s laughable denials that Russia had meddled in American politics, sneering at U.S. intelligence and justice officials who beg to differ.

Trump was given plenty of ammunition to confront Putin by the remarkable set of indictments issued by Special Counsel Robert Mueller last week in his ongoing investigation into Russian involvement in the 2016 presidential election.

The indictments contain such detailed information that they, in effect, sent a message to the Kremlin and its military intelligence branch, the GRU, all but declaring: “We know who you are and where you live.”

‘A powerful tool’

In the hands of a legitimate president, the indictments would have been a powerful tool at such a summit. Trump’s refusal to accept the information, and likely any additional information, from his own intelligence community in order to stand beside Putin and deny Russian involvement has sent the world into shock.

But not yours truly.

As an expert in U.S.-Russia relations who advised the Bill Clinton White House, I believe that what Trump did is perfectly understandable if you believe, as I have argued recently, that he’s a Russian stooge.

Read more: Is Trump Putin's 'stooge?'

Mounting evidence suggests his campaign was helped by Russia. Several key figures associated with him are being investigated; some of the accused are behind bars already. Russia very likely has compromising material on him. Most importantly, Trump, a man of utter venality, has been supported by Russian money for years — the only question is how much.

Trump is also a man whose brain apparently has a disconnect.

How else can one explain him giving a recorded interview that demeaned British Prime Minister Theresa May, his hostess the following day, and then claiming it was fake news (a Russian concept)? This is not stupidity. This is brain malfunction.

Read more: All the lessons Donald Trump has taught us

So what could one have reasonably expected from Trump? After all, he sought a one-on-one with Putin, probably to seek approval for stooge duties well done, and more money — perhaps even a Trump Tower Moscow!

His interpreter is to be debriefed, so we may learn the details. I would not be surprised if the Russians recorded the exchange and release it to embarrass Trump, just as they released the transcripts and footage of his meeting with high-ranking Russian officials the day after he fired FBI director James Comey.

Mixed emotions

They clearly have conflicted feelings about their probable stooge, perhaps preferring to see him replaced with someone a little more stable and effective.

I also expect to hear more damage, more abject abasement on the other points that I listed.

I confess that while I am not shocked, I am surprised at the magnitude of the event. In a presidency marked by a near daily barrage of the ugly and incompetent, Monday’s summit may be one fiasco too far.

Even many of the Republicans in Congress seem to sense that Trump has entered a realm where they themselves wish not to go. The former CIA director John Brennan has called Trump’s actions at this summit treasonous.

Treason is defined as aiding the enemy. Will aiding the adversary suffice? I would say yes. It’s a fitting label for an atrocious act. No one, even anyone in his “base,” can deny that he is failing to live up to his oath of office.

What to do?

The cabinet can invoke the 25th amendment and remove him by declaring him unfit for office — not a hard case to make.

The Republicans in the House of Representatives could screw up their nerve and draw up articles of impeachment to pass on to the Senate for a trial.

We could all wait until November, hoping that the Russians will not corrupt that round of voting and pray that a Democratic Congress will do what the GOP should have done a year ago.

Perhaps the military will give Trump a parade and remove him. After all, extraordinary violations of norms call for extraordinary remedies.

Then again, when he fully absorbs the outcry, Trump will likely just utter two dismissive words: “Fake news.”