Russia says its planes took off from a base in Iran on Tuesday to target ISIS and other militants.
Russia has been conducting air strikes in Syria since the fall of 2015, but this round marks the first time Moscow has used another country as its base for those attacks.
What does this mean for the conflict in Syria and Moscow's relationship with the West? Here & Now's Jeremy Hobson speaks with NPR's Corey Flintoff in Moscow.
This segment aired on August 16, 2016.