President Obama has authorized the deployment of up to 450 more American troops to Iraq to train and assist the Iraqi forces battling the Islamic State, the White House announced on Wednesday, signaling a major shift of focus in the fight against the Sunni militant group. The United States forces will use Al Taqqadum, an Iraqi base near the town of Habbaniya in eastern Anbar Province, as their training hub, the White House said. Mr. Obama opted to send them at the request of Prime Minister Haider al-Abadi of Iraq, and after consultation with Ashton B. Carter, the secretary of defense, and Gen. Martin E. Dempsey , the chairman of the Joint Chiefs of Staff. […]