Ironically, while you're both right, your takedown of his comment is too strong.

Note that he said "cheap" food and fuel. That's a very different thing than just food and fuel. The US has been living this incredibly easy life for the past several decades not because we were living within the resources we have but because we have been exploiting the resources of the world for a price that is massively subsidized by the power of the reserve currency. These are two very different things. Yes, the US has enough food and fuel to live within our borders, but that life will look very different (significantly more work required per resource unit) than the life since 1945. Note I didn't say "would look very different". I said "will". I say this because this is precisely what is happening as we speak. The US access to foreign resources is being chipped away. For that reason, "the American economy" - which is what this commenter said - is collapsing. Our economy was built since WWII on the foundation of access to global resources. As that access is blocked, our economy must shrink, and that is precisely what we are witnessing, with the expected associated pain.