The reason a nuclear conflict with Russia is likely is because, simply put, their conventional forces aren't as good as they're supposed to be. Their navy is like 90% rusting hulls sitting in port, and their few active vessels are decades out of date. Hell, France refused to sell Russia two of the warships they'd ordered over the conflict in Ukraine. Their army is badly understrength, with units manned at levels mostly between 40 and 60%. They rely on largely conscripts who serve for 1 year, making advanced training on complicated systems difficult, and contract soldiers (ie volunteers, like the US Armed Forces) aren't re-enlisting, with dropout rates between 35 and 80%. They privatized their logistics system, and like most privatized industries, it contracted out everything, tripling the costs and causing a corresponding decrease in quality. They then had to un-privatize it, and logistics are now being handled at the brigade level, but there is a shortage of trained officers capable of the task. Their air force is down from 1,600 combat-capable aircraft in 2010 to 1,200 in 2014. Their tank and artillery crews have little live-fire experience, since they cannot afford to expend the shells in training.
Basically, if there is any serious fighting to be done, Russia will have to go nuclear or collapse.