Not too far Dan, as soon as an invasion force crosses into Syria things are going to escalate fast. Invasion is the next step and could happen any second, and I suspect it will happen soon because Russia is a tad bit behind the eight ball trying as fast as possible to get enough asets in Syria to fight a conventional groundwar against a 500,000+ invasion ground force comprised of a Suni coalition.

Russia has air superiority even agianst US technology already. Don't think they won't defend their interests without hesitation. Thats the problem with Russia now, they have advanced their technology far enough in the last 20 years especially in aircraft and anti aircraft That even our stuff can't infiltrate it or defend against it. The SAM 400 system is far more advanced than any system we have.