A Very Stable Genius: Donald J. Trump's Testing of America by Philip Rucker and Carol Leonnig:
Nobody bothered to vet Flynn. There was no review of his tenure as a U.S. military intelligence chief in Afghanistan, which had been the subject of a misconduct investigation. Nor of his time as director of the Defense Intelligence Agency, which President Obama had cut short. Nor of his international consulting firm and his contracts with Kremlin-aligned companies. Nor of his attendance at a 2015 Moscow gala as a guest of Russia, seated at the table of President Vladimir Putin.
Flynn had used the Trump campaign as a gravy train, hoping to better his lifestyle after thirty-three years of relatively low military wages. At the same time he was advising candidate Trump, Flynn was working for the Turkish government and, according to federal investigators, concealing the nature of that arrangement. On Election Day, Flynn published an op-ed in The Hill in which he trumpeted Turkish president Recep Tayyip Erdogan’s cause by comparing his political opponent, Fethullah Gulen, who was living in exile in the United States, to Osama bin Laden. Flynn called for the United States to force Gulen out of the country, stunning his former colleagues in the intelligence and national security communities.
Chris Christie, the New Jersey governor who had endorsed Trump and was the chairman of the presidential transition, was flabbergasted when the president-elect told him he would name Flynn his national security adviser.