The idea of another nation invading Texas and seizing control of its oil fields and then Xi Jinping or whomever saying "We're controlling their oil and we'll be deciding what we're going to do with it in the future" is unthinkable,

They are already doing this to the USA. Why do you think we aren't allowed to develop our oil fields. Someone is holding them in reserve and NOT for US citizens. What about Rare Earth Element mining? We used to have REE mines in the US and someone made a treaty with China that we wouldn't do this mining any more and China would corner the market. What about coal mining? We have many clean ways to burn coal and yet corrupt politicians are coming up with reasons why we can't mine it. What about US steel production? It's been outsourced to China and if we try to back away with have economic warfare.

What about water? The UN wants to control our water and sell the rights to "globalist" corporate entities.

The Obama administration sold 10% of our Uranium to Russia and also tried to sell the Port of Long Beach to China.

Just about every natural resource in the USA is not controlled by the USA. And you call the USA an "empire". All we have is the military.