Iran allowed Russia's bombers to fly from it's base to attack rebels in Syria. This condition leads a growing of pro-Moscow movement. Moreover, sophisticated air-defense system is been provided by Russia to Tehran recently which caused the relation between this two anti-U.S becomes warm. Many analysts interpreted this condition as another Russia's poke to U.S and its ally, also as an advance to be seen as major military power.
T-22M3 and Su-34 tactical bombing took off from Hamedan airbase, in addition they have warned the U.S military to "don't stand out in their way". The targets include the number of ammo depots, command posts, and training camps.
An enormous political effect seems inevitably. Such an explicit bold purpose to maintain Bahar Assad in reign and this war that has been happening for more than 5 years, put Syria in total turmoil. Even though the U.S has accused Russia of indiscriminate, this action means nothing since the Russia maneuver also comes with smashing geo-political thresholds.