It would be nothing to worry about if they were at least semi-rational, like the old Ruskies. Mutually Assured Destruction would keep everyone packing but nobody drawing down. But the Chinese are a whole different kind of loose cannon. Run by kooks, zealots and suits (I don't know which is worse), they could go full retard at any moment.

But in reality it's most likely saber rattling to extract favorable terms from undefended trading partners. We should know that, we practically invented that game.