Russia and middle east will obviously team up. Ukraine, Belarus, Poland, Turkey, Finland will fall within the first month or two. The deciding factors of WW3 would be who Germany sides with and if the USA will have both China and Japan on their side. If they are it makes it a one front war for the USA.
The middle-east is divided. The Shiite nations, such as Syria and Iran might team up with Russia, while the Sunni nations such as Saudi Arabia and Kuwait will side with the United States. Germany will side with the US, as it is a NATO member. And there is no chance that China and Japan will be fighting in the same side, as they are mortal enemies.