US military command responsible for Syria hates the idea of cooperating with Russia. Russia has intentionally given US wrong flight plans to alter US movements and divert US air support. Russian aircraft have attacked US led forces and endangered US personnel. Russian alliance with Iran and Syria also makes cooperation unlikely. Russia has also joined with Turkey attacking US supported Kurdish fighters. Each of these allies Iran, Turkey, and Syria want Syrian territory and control divided up as the campaign to eliminate ISIS succeeds and shifts to a political struggle. Russia wants to control this process to serve their purposes-- primarily giving Russia air bases in Turkey, Syria, and Iran