I don't think we have free trade (although I would certainly support it!). I think we probably are richer than we were pre-war. We're just not at the peak we were after the war when we had a monopoly on success.
We also profited greatly supplying the wars. We haven't had a "market" like that since then. The US was mostly its own customer during the cold war.
What other major industrial nation was not devastated during either World War? (I guess you can say "Canada" but I'm not sure how "major" or "industrial" they would have been in WWI).
My question is: the standard Ricardian argument for international free trade assumes that as trading partners become more productive, all trading partners benefit. Do you think this is the case? Certainly the original post does, as confirmed in his response.
If that is so, why would other countries becoming better at making things make us poorer?
Do you believe in the Ricardian argument for free trade? If so, why did we not become richer as other countries became better trading partners?