Almost from the moment he took office, President Trump seized on a theory that troubled his senior aides: Ukraine, he told them on many occasions, had tried to stop him from winning the White House.
After meeting privately in July 2017 with Russian President Vladimir Putin at the Group of 20 summit in Hamburg, Trump grew more insistent that Ukraine worked to defeat him, according to multiple former officials familiar with his assertions.
The president’s intense resistance to the assessment of U.S. intelligence agencies that Russia systematically interfered in the 2016 campaign — and the blame he cast instead on a rival country — led many of his advisers to think that Putin himself helped spur the idea of Ukraine’s culpability, said the officials, who spoke on the condition of anonymity to describe internal discussions.