WASHINGTON – President Donald Trump has ousted the Pentagon's top policy official who had certified last year that Ukraine had made enough anti-corruption progress to justify the Trump administration's release of congressionally authorized aid to Kyiv in its conflict against Russian-backed separatists. John Rood resigned Wednesday, saying he was leaving at Trump's request. The Trump administration's delay in releasing the aid to Ukraine was central to the president's impeachment by the House on charges of abuse of power and obstruction of Congress.