Reddit reviews Power Transitions: Strategies for the 21st Century

Russia is dissatisfied with the status quo being sustained by the United States and the West -- and rightly so. They are also a still-waning ex-superpower. These two factors combined makes the odds of conflict much more likely than they would be in the absence of either factor (see Tammen 2000).

The important factor, however, is whether or not China will challenge the current status quo when they inevitably pass the United States in productivity, GDP, etc. Russia does not want to ally with the West -- that is becoming increasingly clear. However, their dissatisfaction is more like that of a petulant child whose toys are being taken away. China's dissatisfaction would mean a lot more because they are coming of age as opposed to declining like Russia is. So Russia will ally even more strongly with China when this happens if they opportunity presents itself.

Russia combining military and economic power with China would mean big trouble for the Western powers and their status quo.