I haven't really heard much as to the RELIABILITY of China's nuclear armaments, but I do know that it seems they SORELY lack behind the US, and even Russia, in technology level.
Current number say that while China may have a few thousand warheads, they have but TEN ICBMs to launch them; each ICBM can only use a single warhead, is fairly dated, and are kept DISSASEMBELED in storage sites well-monitored by US (and other) sattelites.
In other words, by the time China could possibly even ASSEMBLE a missile to strike the USA, (or Europe, Canada, Australia, or any other modernized country other than Japan and South Korea, for that matter) let alone TARGET and FIRE the missile, the US military could leisurely select an option for disabling the missile before launch; no "Star Wars" type missile defense shield needed! America could simply launch one of its own land-based ICBMs, and nuke the launch pad right then and there.
China may have a lot when it comes to numbers, but they have old technology; their thousands of jets are pathetically slow compared to any modern NATO design, and their land-based armaments are all old Soviet stuff; vintage 1970's tanks, and so on.
As for China's message for the USA? DEFINITELY old news. They quite honestly need to change their broken record. Perhaps they might be more interesting if they actually adopted a full capitalist system in earnest, rather than outwardly expressing communism while secretly trading and importing from the USA to prevent the collapse of their "economy."
Wake up, George Lucas... The Matrix has you...