Incoming UN Secretary General Antonio Guterres says, the Syrian conflict has become a cancer on a global scale. He hoped that Washington and Moscow will overcome their differences to help end the crisis. <br/><br/>The war has caused not only the suffering of the Syrian people but also sparks violent reactions which in some cases lead to terrorist acts, the former Portuguese premier says. The conflict began in 2011 as an uprising against President Bashar al-Assad but quickly morphed into a civil war after the regime unleashed a brutal crackdown against dissents. The war has killed thousands of people and forced millions to flee their homes.