I would actually guess that they try to use undercover/spec ops to take out KMT first. Air will operate against military targets and to help the undercover units, but I don't expect the PLA to fully attack unless US/Japan attacks.
Even with China's current status as a disarmed nation, having an extremely large economy translates to incredibly high firepower. Since it's all focused in the home front, the level of strikes may exceed what US can do several times over. If they start shooting like that inside China, it will kill many of the undercover infiltrators too. So they have to wait out the undercover ops first before considering full air + artillery.