
Russia is the richest country in the world in terms of natural resources. After the Soviet Union went bankrupt, Russia invited many international corporations in to develop its natural resources with revenue sharing as the contingent reward. It worked well. Twenty years later, Russia is the world's second-largest exporter of oil and natural gas and the seventh-largest holder of American debt.
China is the most populous country in the world with 1.3 billion people and could well use the natural resources to its north. Without Russia's nuclear arms, how long would China take to acquire those natural resources?
Russia is not suicidal.