"You think China is going to invade America with a platoon of MPs from Haiti and a couple loading docks in Panama?"
There is no one thing that worries me about Red China. It is the totality of what they are doing as part of the rapidly growing Eurasian Alliance (Russia, Red China, EU, Iran, etc.).
Well, I won't dispute that a genuine China-Russia-Europe alliance would be formidable, but that prospect seems so remote in my view that it's in the realm of fantasy.
Leaving aside French delusions of grandeur, the European Union remains a geopolitical incoherence, that'll spend the next two decades at least just consolidating itself and expresses little interest for military confrontation with anyone.
Russia is an internal disaster zone on so many levels that can barely project the remnants of its power across its own polity, much less across Eurasia. It is also totally dependent on the largesse of outsiders in one form or another.
As for China, they are little more than a conceited Third World nation that just happens to have such a huge population that enough of them have fleeced the rest that they somewhat approximate the prowess of 'lesser' nations.
All three are walking on a tightrope of their own making and it's just as like - I would even say far more likely - that all three will collapse (the EU in a geopolitical sense) than that they will harmonize some grand anti-American alliance. Even if they manage to coordinate some efforts, it would not take long at all before their own rivalries stormed to the forefront.
There is one thing that definitely unites them: a desire to make money. In the modern world that generally means profitting off of Americans, and they know it.