Russian military intervention in the Syrian Civil War

On 30 September 2015, Russia started military intervention in the Syrian Civil War,  consisting of air strikes primarily in north-western Syria by Russia against militant groups opposed to the Syrian government, including al-Nusra Front (al-Qaeda in the Levant), the Islamic State and the Army of Conquest  The Russian Air Force had significant ground support from the Syrian military, Iranian Revolutionary Guards, and allied militias.  Prior to this intervention, Russian involvement in the Syrian Civil War had mainly consisted of supplying the Syrian Army. Russia intervened after a formal request from the Syrian government for military help against rebel and jihadist groups in Syria.  Russian officials have acknowledged their objective is to help the Syrian government retake territory from various opposition groups, including groups backed and armed by the United States.  The situation as it developed in October 2015 was widely assessed to be a proxy war between the United States and Russia.