RIYADH, Saudi Arabia — U.S. Secretary of State Mike Pompeo said Monday that President Donald Trump’s threat to devastate NATO ally Turkey’s economy if it attacks U.S.-backed Kurdish fighters in Syria underscores America’s commitment to its partners. Pompeo said he had yet to speak with Turkish officials or Trump about the president’s tweeted threat and that he assumed Trump was referring to the imposition of sanctions should Turkey take military action against the Kurds in Syria, U.S.