WASHINGTON (Reuters) - U.S. President Barack Obama's envoy charged with building the coalition against the Islamic State militant group arrived in Iraq on Thursday and will also visit Belgium, Jordan, Egypt and Turkey, the State Department said. The group has overrun wide swaths of territory in Iraq and in Syria in an onslaught that has threatened the integrity of the Iraqi state and created even more instability inside Syria, which is embroiled in a three-year civil-old war. ...