I'll direct you to a book: The Wages of Destruction by Adam Tooze (Penguin, 2006).

It's a long book, but very good. State intervention was commonplace, and Tooze does a good job arguing that it was directed toward achieving self-sufficiency, via autarky and, eventually, war. The German economy struggled with balance of trade and foreign exchange, and it influenced Nazi economic policy. It's been long enough since I read the book that someone else might be able to summarize it better, but if you want a one-volume answer to your question you could do worse than starting there.