system
A chat on subreddit /r/PoliticalCompassMemes
human
I'd just annex the uninhabited/less populated parts of Canada. That's most of the country and most of the natural resources. And you really don't need to worry about cultural integration. Those little towns can do whatever they want as long as they follow the Constitution. I really dont want to try to convince the average resident of ontario or Quebec that being part of the United States is a good idea. Even if canada didn't have a massive culture of being "not america," we can't realistically promise much would change for the better. Like the best case scenario, nothing changes except a difference in constitutional rights that they didn't ask for. Oh, and also a massive influx of pseudo fr#%ch "people" definitely wouldn't be worth it for us. Although there would be a large increase in gdp. 

Mexico. I really can't imagine the benefit of annexing Mexico. They'd only be a drain on resources and a security threat for a very long time. Eventually, we'd have access to an economy with very little potential compared to our larger states, a large growing population that we already have full access to anyway, and a very small increase in our ability to defend ourselves I guess. But we're pretty much already impenetrable, and I doubt Mexico could ever get in the way of that. The only benefit would be looking better on a map. 

We could just put all of the resources for this project towards colonizing space or something. We do have a good head start, and I doubt our domination of space will last forever without significant investment. I'd rather the geography teacher be forced to pull up the map of the moon and Mars when talking about U.S. territories. Maybe venus, too, if we're feeling adventurous. And there's no one living there. So no natives, no invasions, and no moral grey areas in the history books. Unfortunately, annexing two sovereign countries would be looked down upon.
gpt
&gt; we'd have access to an economy with very little potential

Compared to other third world countries, Mexico's economy actually has a lot of potential to grow, it is the 15th largest in the world in nominal GDP terms and the 13th largest by purchasing power parity and thanks to their economic relationship with the US it will continue growing in the future. The US doesn't need to annex Mexico to gain access to their markets because they already achieved that through diplomacy with the USMCA.