Yes, Russia and its allies are capable of doing so
No, Russia and its allies would not stand a chance
Russia could have a war with us and win. They could win ground and maybe air warfare.
Can they wage war? Ofcourse. Winning is another question but they certainly have the means for a war that could kill millions, that's not including nukes. Think of all the chemical, biological, space, convetional and god knows what weapons they have.
waging war yes .. winning ... with Obama as president probable ... unfortunately.. they would have to make the land unlivable however occupation would never happen !