President Donald Trump’s twitter tirade against MSNBC’s Mika Brzezinski last week revealed more than his continued willingness to demean his office — and women.

This tawdry tweet points to a much more dangerous consequence of Trump’s war on much of the media. His attacks on journalists blind him to the real onslaught of fake news.

I refer to the campaign of disinformation, propaganda and cyberwar being waged by Russia to undermine U.S. and European democratic institutions. That includes covert, and overt, meddling in elections.

European leaders recognize the threat, U.S. intelligence agencies have described it and U.S. senators, in rare bipartisan agreement, want to confront it. Yet, as Trump prepares to meet Vladimir Putin at the G-20 summit in Hamburg, he still denies that Russia’s fake news campaign is real.

That threat, and possible countermeasures, were detailed in a fascinating conference in Washington, D.C., last week, part of a weeklong series of events called “Disinfoweek” co-sponsored by the Atlantic Council, Germany’s Konrad Adenauer Foundation, and other U.S. and European organizations.

U.S. Sens. Chris Murphy (D-Conn.) and Rob Portman (R-Ohio) in a heartening display of bipartisanship, argued that Russia’s disinformation campaign in the 2016 election was about something much bigger than undermining Hillary Clinton.

“Vladimir Putin and his disinformation network are not Republicans, they are opportunists,” Murphy said. “It is just a matter of time before they train their sights on the Republican Party.”

The focus on day-to-day investigations into the Trump administration and Russia, said Murphy, distracts attention from the story of what actually happened. There were “rooms (in Russia) filled with hundreds and hundreds of Russian-paid trolls, troll factories, people that were every single day in enormous numbers standing up fake news, fake accounts inside the United States to try to spread a series of lies to influence our election,” he said.

“The threat is much bigger than one president,” added Portman. “It is much broader than that.”

Portman is correct. The use of disinformation as a KGB foreign-policy tool dates back to the Soviet Union, but has become more central to Russian foreign policy. The spread of social media platforms and technology means that misinformation can be spread like wildfire while covering up the original sources.

Portman is also correct that the public debate over Russia’s role in the 2016 election has “too often devolved quickly into partisanship and sometimes hysteria” rather than letting the ongoing investigations get to the bottom of Russia’s involvement. However, that’s largely because Trump insists that the investigations are a “witch hunt” and coverage of the investigations is fake. He refuses to recognize Portman’s point: This is about something much bigger than him.

Europe is far ahead of the United States in confronting the Russian threat, because European leaders recognize the problem. On the continent, the Kremlin openly funds far-right and far-left political groups that are anti-American, anti-NATO and anti-European Union. The Russians meddled in May during French elections and in preparations for German elections in the fall.

The Kremlin’s goal, European participants said, is to undermine faith in democratic governments and promote anti-Americanism. It seeks to promote Putin’s semiauthoritarian model as a nationalist, religious conservative alternative to pluralist democracy. (Think this is nuts? Just read what key Trump adviser Steve Bannon has written praising Putin along these lines.)

However, many European leaders have fought back, organizing agencies to track Russian disinformation.

Portman and Murphy believe the United States must fight back, too. They co-authored the 2016 Countering Disinformation and Propaganda Act, now law, which will provide millions to counter propaganda from Russia and China, and help U.S. allies to do likewise.

Yet it is hard to see how the United States can expose Russian information, and make the American public more aware, when the president refuses to confront that threat or even admit it exists. And when he continues to condemn legitimate U.S. media — not Sputnik or RT — as fake news.

When Trump meets Putin in Hamburg, he’ll have the chance to tell the Russian president bluntly that the disinformation must stop.

Or he can ignore the subject, and keep on tweeting about Mika and “fake news.” That will hand Putin a huge win in his disinformation wars.

Trudy Rubin is a columnist for the Philadelphia Inquirer.