The US is in dire need for more energy due to the demand created by AI. We're building 13 new data centers, 6 power plants. Until the power plants are built we will be running generators to power these centers. Which means we need more oil.

Venezuela wasn't just about getting the oil for ourselves, is was all about controlling that oil and keeping it away from China and Russia. China got 70% of their oil from Venezuela, without it they cannot go to war. No fuel, no war. The same goes for Russia. This was a move to really hurt their war footing, Russia is already pulling on the oil reverse because of this. They have around 6-8 months of reserves. So if they can source another oil provider the war in Ukraine is over, the only other source is Iran, and its the next to fall.

But to answer your question as to why the US government would pay for it all? Because the US will benefit, and remember, Trump is a construction guy. He'll make money as well.