An emerging consensus among long-time PLA observers, including within the US intelligence community, is that the Chinese military has successfully achieved a far-reaching qualitative advancement in its warfighting capabilities since the beginning of this decade. The PLA is quickly becoming an increasingly credible threat against Taiwan and could even begin to pose a challenge to US military preponderance in East Asia in the next decade if the momentum is sustained.For any move on Taiwan, obviously the air and naval forces are going to be critical - ever since Operation Sea Lion, military planners have wanted air superiority before any attempted amphibious invasion. Like the British during "Their Finest Hour", the Taiwanese have always planned on winning any future war with the mainland "in the straits" - that is, they need to successfully defeat the PLAAF (Beijing's Air Force) and the PLAN (People's Liberation Army Navy, a damn weird name for a fleet if you ask me) to forestall any invasion.
The PLAAF now has around 300 advanced Russian and Chinese combat aircraft, which are armed with sophisticated munitions. Air force chiefs, however, also face the pressing challenge of coping with the spreading obsolescence that affects the rest of its inventory of more than 3,000 combat aircraft.
Meanwhile, according to the above article 90% of the PLAAF's inventory is obsolete. That nasty 10%, however, is pretty damn good. It's worth asking whether China is yet ready to risk their best 10% in a war with the US, Japan, and Taiwan. Losing the best of their Air Force would essentially leave the Mainland with nothing but 1970s-era Soviet Migs. Replacing the other 2,700 combat aircraft is going to take a long time - at a guess, I'd bet on a decade at least. If Beijing is rational (and there's little reason to believe they aren't) they'll wait to start something until they can afford to lose. Who knows what else will happen in the meantime?