Mostly just context. The same way you can tell the difference when вопрос means "issue" and when it means "question", or when политика is referring to politics in general or a specific policy.
Thank you for your explanation and helpful examples. Now I see. Actually that is what I supposed, yet it remains so weird to me. One should get used to such a strange thing. I don’t know why I feel so comfortable with our "политика" meaning both policy and politics.