I went looking and found this: https://en.m.wikipedia.org/wiki/Energy_efficiency_in_transport

And yep transport via boat is the most energy efficient.

That said I’m going to assume that OP in this thread is not talking about logistics efficiency, but rather a downturn in a demand for goods.

Isn’t shipping via boat one of the most energy efficient forms of goods transport we have as a species?

I have full confidence that the US Military could take Greenland, I don’t have confidence that the US could deal with the international fallout that would come from it.