"Votel, who has headed U.S. Central Command for just seven weeks, became the highest-ranking U.S. military officer known to have entered Syria since the U.S. began its campaign to counter the Islamic State group in 2014. The circumstance was exceptional because the U.S. has no combat units in Syria, no diplomatic relations with Syria and for much of the past two years has enveloped much of its Syria military mission in secrecy."