DUBROVNIK – U.S. Secretary of State Mike Pompeo pledged Friday that Washington will remain engaged in the Balkans where China and Russia have been gaining political and economic influence.Pompeo spoke in the Croatian Adriatic Sea resort of Dubrovnik, the last leg of his European tour that also included stops in Greece, Italy and the Vatican.“The United States no longer leads from behind,’’ Pompeo told reporters at a news conference held on the terrace of a hotel overlooking the medieval walled city.