Peter Bergen is CNN's national security analyst, a vice president at New America and a professor of practice at Arizona State University. He is the author of "United States of Jihad: Investigating America's Homegrown Terrorists." The opinions expressed in this commentary are those of the author; view more opinion articles on CNN.

(CNN) How much longer can the foreign policy leaders in President Donald Trump's Cabinet stick by this President?

The Helsinki, Finland, summit will surely go down as one of the worst-ever presidential performances on the international stage. Not since President John F. Kennedy was thoroughly intimidated when he met with the Soviet leader Nikita Khrushchev in Vienna, Austria, in 1961 has an American president been so completely and artfully outflanked by his Russian counterpart.

At a press conference in Helsinki standing next to Russian President Vladimir Putin, instead of endorsing the unanimous finding of US intelligence agencies that Russia interfered in the 2016 presidential election, Trump observed that Putin was "extremely strong and powerful in his denial."

Well, that settles it then! We will always take the word of Putin, a former longtime KGB official whose actions around the world have run counter to American interests, against those of America's key intelligence agencies.

For good measure, Trump dumped on his own country, "I think that the United States has been foolish. We've all been foolish. We're all to blame." Really? In fact, as special counsel Robert Mueller's investigation has painstakingly revealed, the ones to blame are a small coterie of officers in Russia's military intelligence agency GRU, acting no doubt under the orders of Putin.