Joe displayed his inability to effectively handle the U.S. pulling out of Afghanistan. Our allies are no more because he turned on them.
With Joe and Milley's lack of leadership, I think both Russia and China know that right now the U.S. is ripe for the taking. With no true allies left, who would even help us??
WADR, I don't think an invasion of the U.S. is forthcoming. Regardless of the 'woke' rot at the top, the U.S. military is, in general, a top-notch force, and they would be fighting for their homes, not just some far-off outpost where they've been told, contrary to all appearances, the U.S. has an interest.
Besides which, what would that gain them, other than a huge war - WWIII on steroids - total consumption of their existing forces, and possibly a nuclear exchange.
And for what? For land that isn't contiguous with their current boundaries, and which would be full of resistance movements?
They have better things to spend treasure and military forces on, and those don't currently involve an invasion of the U.S.
What they do involve, is Russia gaining effective control over Ukraine, and possibly other near east European countries, and China finally bringing Taiwan back into the family fold.