Who should take responsibility for the cold war?

The Cold War was the result of market forces.

These market forces include abstract concepts such as fear, and tangible concepts such as level of industry, comparative advantage, and technological capabilities.

If a government decides it wants to allocate more taxes than are necessary to defense spending, its morality and ethics may be called into question, but it is the responsibility of it's citizens to decide what tax revenue is used for what.

The citizenry is responsible for government actions, no matter what model of society they exist under.