As Donald Trump began his meteoric rise to the presidency, the Obama White House summoned Ukrainian authorities to Washington to coordinate ongoing anti-corruption efforts inside Russia’s most critical neighbor. The January 2016 gathering, confirmed by multiple participants and contemporaneous memos, brought some of Ukraine’s top corruption prosecutors and investigators face to face with members of former President Obama’s National Security Council (NSC), FBI, State Department and Department of Justice (DOJ). The agenda suggested the purpose was training and coordination. But Ukrainian participants said it didn’t take long — during the meetings and afterward — to realize the Americans’ objectives included...