Yesterday three high ranking Russian officers were killed in an "ISIS attack" in eastern-Syrian. It is likely that they were killed by U.S. special forces or insurgents under U.S. special forces control. The incident will be understood as a declaration of war.
The U.S. Central Command in the Middle East wants the oil fields in east-Syria under control of its proxy forces to set up and control a U.S. aligned Kurdish mini-state in the area. The Syrian government, allied with Russia, needs the revenues of the oil fields to rebuild the country.
Read the article:
http://www.awdnews.com/society/u-s-centcom-declares-war-on-russia-us-military-forces-can-occupy-russia-border-cities-in-48-hours