LONDON, September 27 /TASS/. The Russian military operation in Syria has weakened the Islamic State terrorist group and radically changed the idea about Russia’s military potential, the London-based International Institute of Strategic Studies (IISS) said in its "Strategic Survey 2016: The Annual Review of World Affairs" on Tuesday.

"Russia’s entry into Syria’s civil war with a bombing campaign that began in late September 2015 surprised observers and officials across the world. By summer the following year, the campaign had achieved several of Moscow’s objectives, especially the prevention of regime change and a reinforcement of Russia’s status as a great power," the survey’s authors said.

Russia started its operation against the Islamic State and Jabhat al-Nusra terrorist groups (both of which are banned in Russia) on September 30, 2015. The Russian bombing campaign has helped the Syrian troops to liberate about 400 populated localities and has inflicted serious damage to the illegal oil trade, which is the main source of income for terrorists. All major supply routes for weapons and ammunition were blocked. On March 14, Russian President Vladimir Putin ordered a withdrawal of the main part of the Russian Aerospace Forces from Syria.

The Russian head of state said that the Russian militaries had fulfilled most of their military tasks in Syria. Two Russian military facilities continue operation in the Syrian territory: an airfield in Hmeymim and in Tartus. The Russian servicemen continue fighting against the terrorist groups in Syria.