Iran boosts military support in Syria to bolster Assad

LONDON/ANKARA (Reuters) - As Syria's war nears the start of its fourth year, Iran has stepped up support on the ground for President Bashar al-Assad, providing elite teams to gather intelligence and train troops, sources with knowledge of military movements say.

This further backing from Tehran, along with deliveries of munitions and equipment from Moscow, is helping to keep Assad in power at a time when neither his own forces nor opposition fighters have a decisive edge on the battlefield.