The humor writer Andy Borowitz recently joked that Donald Trump had been named the Kremlin’s “employee of the month.” I giggled at that, and then winced. It’s painful even to joke about.

Some of the most explosive reports about America in the last few days appeared in Israeli newspapers. They suggested that American intelligence officials had warned Israel to “be careful” about sharing classified information with the Trump White House, for fear that it would be given to Russia.

American intelligence officials reportedly cautioned that Vladimir Putin might have “leverages of pressure” to extort Trump. That presumably was a reference to the hanky-panky recounted in the dossier alleging that Moscow compromised Trump by filming him cavorting with prostitutes in a Moscow hotel.

Perhaps more troubling are suggestions of collusion between Moscow and the Trump campaign.

Trump strongly denies all this, the dossier has zero public evidence behind it, and it should be treated with skepticism. But it reflects an unprecedented uncertainty: There is a disorienting kernel of doubt about whether we can fully trust the man who will occupy the Oval Office.