The resignation of Michael Flynn, U.S. President Donald Trump's national security advisor, leaves a vacuum at the top of the White House's foreign policy structure as the new administration tries to reshape America's relationship with Russia and calibrate a response to the latest missile test provocation from North Korea.
Flynn was forced to resign after less than a month in office for making potentially illegal contacts with the Russian ambassador in Washington, an issue that may complicate Trump's stated goal of improving relations with Moscow and possibly lifting U.S. sanctions against Russia.
