The dangers that flow from Mr. Trump’s character are not just risks that would emerge if he became president. It is already damaging our national security.

President Vladimir V. Putin of Russia was a career intelligence officer, trained to identify vulnerabilities in an individual and to exploit them. That is exactly what he did early in the primaries. Mr. Putin played upon Mr. Trump’s vulnerabilities by complimenting him. He responded just as Mr. Putin had calculated.

Mr. Putin is a great leader, Mr. Trump says, ignoring that he has killed and jailed journalists and political opponents, has invaded two of his neighbors and is driving his economy to ruin. Mr. Trump has also taken policy positions consistent with Russian, not American, interests — endorsing Russian espionage against the United States, supporting Russia’s annexation of Crimea and giving a green light to a possible Russian invasion of the Baltic States.

In the intelligence business, we would say that Mr. Putin had recruited Mr. Trump as an unwitting agent of the Russian Federation.

Michael Morell