At present, per yesterday’s Yisrael Hayom, quoting numerous Arab journalistic sources, it looks like either the Revolutionary Guard of Iran or Hizbollah, or both, are being used within Syria to suppress the demonstrations. Witnesses say that they were shot at by bearded men in uniform, and the Syrian armed forces are all clean-shaven, using weapons that are not issued to Syrian regulars. Apparently, Assad has had a few too many mutinies among his own troops.
Iran can't afford to lose Syria as a base of operations against Israel and to support proxies in Lebanon. Hopefully the Israelis can exploit the current chaos to their advantage.