I wonder if something happened where the water supply situation out west became so dire that pumping water from the great lakes was the only viable solution to it, if the US would annex Canada in that situation to not have to abide by international agreements that the great lakes can't be pumped for water.

Keep in mind the US is an atrophying empire at this point that's increasingly having a difficult time keeping things working properly, atrophying empires tend to do things like this to sustain themselves at all cost so who knows