HAMBURG—What little we know so far about the sit-down between Donald Trump and Vladimir Putin at the G-20 summit in Hamburg today is that the Russian president was “delighted” to get together with Trump and feels (as any former KGB agent would) that “personal meetings” are the best way to deal with issues. Trump, for his part, said what he often says when meeting foreign leaders: “It’s an honor to be with you.”

Shouted questions during that brief grip-and-grin photo op elicited no response about whether the Russian hacking that helped Trump win the presidency would be discussed between them. Then, for well over two hours, almost five times longer than anticipated, they talked. Was Trump laying down the law? Or was Putin explaining to him the Russian version of how the world should work, and cordially filling in the many gaps in the American president's understanding of, among other things, basic facts?

In the very tight closed-door session Trump was accompanied only by U.S. Secretary of State Rex Tillerson, which is to say an amateur politician and an amateur diplomat, up against Putin, a veteran of 17 years in power, and Russian Foreign Minister Sergey Lavrov, one of the world’s most accomplished (and slippery) statesmen.

Afterward, Tillerson told the press the meeting had "rightly focused on how do we move forward from something that may be an intractable disagreement at this point." Right.

Lavrov told reporters that Trump said there was "not a single" proof found about "Russia's alleged involvement" in the U.S. elections. According to Lavrov, President Putin made very firm statements that the charge was not true and that the Russian leadership did not get involved and Trump "accepts these statements."

So, it’s unlikely the public will learn much now, if ever, about how that key question blighting American democracy—the way Russia gamed the U.S. elections—really was addressed. We're just "moving forward." And skeptics are left to make of it what they will, as The Huffington Post did with the handshake photo and the headline: “Trump Meets His Maker.”

There obviously are issues where Russia and the United States can find common ground, but at best they are American appeals for Russian help dealing with intractable conflicts, like the growing threat to the U.S. and the world from North Korea, as well as the continuing crisis in Syria. The AP reported after the meeting that Russia and the U.S. have agreed to a vague “cease-fire” in southwestern Syria.

In many cases, however what the Russians are looking for—and might get—are outright concessions by the Americans to blatant Russian aggression, whether on the battlefields of Ukraine or by waging wars on Western democracy in cyberspace.

So it's important to remember that sanctions were not imposed on Putin’s Russia because Western leaders don’t like his style, or because they are Russophobes. They were imposed because of Putin’s shameless acts so dangerous to the sovereignty of Russia’s neighbors and to his adversaries that, short of open war, there were few other suitable responses.

And make no mistake, Putin sees the U.S. as an adversary, no matter how naïve about that subject Trump might have been going into this meeting or, God forbid, coming out of it.

What Putin knows, and certainly will play on, is Trump’s notion that the so-called Islamic State and other forms of “radical Islamic terrorism” are an enormous threat to Western or, as Putin and Trump may agree, to “Christian” civilization. That was the core message of Trump’s speech in Poland on Thursday, and one that Putin—allied as he is with the Russian Orthodox Church—can use easily as a source of “mutual understanding.”

Putin also knows that Trump’s focus on terrorism is useful to Trump politically, because it’s also been useful to Putin: the exploitation of fear and insecurity is a tried and true method of demagogues everywhere, whether the threat is real, exaggerated, or manufactured.

It's telling that Putin, commenting afterward, said that among the issued discussed were "fighting terrorism and cybersecurity," lumping the two issues together while denying, of course, that Russia meddled in America's elections or anybody else's.

So, moving forward ... .

The two leaders might even find common ground deploring the violent protests of the “Black Bloc” anarchists on Hamburg’s streets, who laid siege for a time to the hotel where Melania Trump was staying, making it impossible for her to leave for a tour of the harbor with any modicum of security.

"It's not our problem if the wife of Donald Trump cannot attend her appointments," Werner Rätz, one of the protest organizers, told The Daily Beast.

As of sundown on Friday, after 24 hours of violent demonstrations welcoming the G-20 to Hamburg's "hell," scores of police had been injured, almost a dozen protesters had been hospitalized, and at least 46 had been arrested.

Josephine Hüetlin reported from Hamburg and Christopher Dickey reported from Paris.