My understanding with Norway is that they saw their North Sea oilfields as social engineering tool. One aspect was to put away much of their royalties for a “rainy day”. Norway is the only western country to have a positive balance (this was about 10 years ago, I’m not sure about today).

As for FDR’s New Deal, I believe it put a lot of people to work that would not have found work had the economy been left to itself. Too many idle people are a recipe for social unrest. But you might be right that demand did not significantly increase in the 1930s.

For a country that was supposedly broke from the recession, it’s amazing how USA and other nations put together a wartime economy. Monetarist economics was maxxed out in these times.