If I were an enemy to the USA
I'd take down California as my first big step.
Run it into the ground. Turn it into a garbage dump. Run out the good productive citizens then put in the most radical left wing lunatics I could find to get into office.
Then, divide them from the rest of the USA.
Then I'd push for them to secede. The rest of the country would be ok with it anyways.
Then, I'd put my puppet government into place and become allies with China or Russia and open up ports and bases for them and cut most of the USA ports off for trade with the US except for super high tariffs.
If I were an enemy of the USA….
But turns out I'm not.
Merry Christmas!