“Russia and the Syrian regime have chosen to pursue a military course, inconsistent with the Cessation of Hostilities”
Axiomatic differences.
Kerry thinks playing nice is paramount.
Putin & Assad think killing enemies is paramount.
Not compatible.
When the USAF bombed the syrian base and killed dozens of Syrians and maybe some Russians too, and then stood by as ISIS overran the base and butchered the wounded, I suppose the fact that we said “ oops” was supposed to be enough to keep Russia’s hands tied with a peace treaty