Bonnie Glaser gets it about right regarding China's newly announced Air Defense Identification Zone, or ADIZ: "I don't know that this is specifically directed against Japan, so much as it is the Chinese feeling that every modern country should have an Air Defense Identification Zone." 
Just to make it clear. An ADIZ is not a "no fly zone" or extension of sovereignty. It is defined by the speed of modern enemy jets and the amount of time needed to challenge, identify hostile intent, and prepare air defenses.
When unidentified planes entire an ADIZ, they are required to identify themselves.
Per Xinhua, the new regulations require:
1. Flight plan identification. Aircraft flying in the East China Sea Air Defense Identification Zone should report the flight plans to the
Ministry of Foreign Affairs of the People's Republic of China or the Civil Aviation Administration of China.
2. Radio identification. Aircraft flying in the East China Sea Air Defense Identification Zone must maintain the two-way radio communications, and respond in a timely and accurate manner to the identification inquiries from the administrative organ of the East China Sea Air Defense Identification Zone or the unit authorized by the organ.
3. Transponder identification. Aircraft flying in the East China Sea Air Defense Identification Zone, if equipped with the secondary radar transponder, should keep the transponder working throughout the entire course.
4. Logo identification. Aircraft flying in the East China Sea Air Defense Identification Zone must clearly mark their nationalities and the logo of their registration identification in accordance with related international treaties. 
I like that. In a tense area of the Pacific, potentially hostile planes are supposed to identify themselves when they are flying around. You don't want somebody shooting at your plane, all you have to do is get on the radio. Good. Extend that ADIZ out to Midway. Maybe it'll stop World War III.
The ADIZ looks like it's stabilizing, not destabilizing the region.
Put me on the same page with the PRC Ministry of National Defense spokesperson:
Having established its own air defense identification zone in late 1960s, Japan has no right to make irresponsible remarks on China's setup of the East China Sea Air Defense Identification Zone, Yang said.
According to Yang, Japan has frequently sent military planes in recent years to track and monitor Chinese military planes which were conducting normal exercises and patrols above the East China Sea in the name of entering its own air defense identification zone, which severely undermined the freedom of over-flight and made safety accidents and unexpected incidents highly likely.
Yang also accused the Japanese officials of using the media to maliciously report about China's legal and normal flights in an attempt to confound public opinions and create oppositional emotions.
"Facts have proven that it is Japan who has been creating tense situations," Yang said. 
For support for Yang's assertion, I invite readers to review my post about the flight of the Chinese turboprop between two Japanese islands in August, which morphed into a fighter plane intrusion on its way through the media sausage factory.
China's declarations were not good enough for the Japanese and Western press, which embarked on another round of "assertive China" hysterics.
The most dishonest element was characterizing the zone as primarily a piece of Senkaku Islands-related shenanigans.
I don't doubt that China is trying to slice the East China salami, and use the ADIZ to strengthen its administrative claims over the area of the Senkakus, but look at the map below provided by MIT's Taylor Fravel. The yellow line is the Chinese declared ADIZ. The red zone is the overlap with the Japanese ADIZ (Remember it's not an exclusion zone. Overlapping is OK. It's a "you've got to talk to the other guy's air traffic control when you fly in there" zone):
It's the entire East China Sea north of Taiwan. It's targeting Japan, to be sure (for valid reasons) but the Senkakus are only a tiny part of it - that little bend in the lower right quadrant otherwise wouldn't cover the Senkakus. That means that when Japan's SDF flies planes over there, they should talk to the PRC. I think that's a good thing.
People with long memories - obviously not including the main media outlets, pundits, or their readers-might have noticed the parallels between the ADIZ furor and the vaporings over the new PRC Coast Guard regulations in the South China Seas at the end of last year.
That was also billed as a "worrying escalation" but it was a nothingburger.
The big difference between the Coast Guard regulations and the ADIZ is that the United States government soft-pedaled the Coast Guard issue but got its back up on ADIZ with statements from Chuck Hagel and John Kerry that the Japanese found extremely gratifying.
I think US dismay was not elicited by the PRC's logical desire to have foreign planes talk to the PRC when they approach PRC airspace.
I think it had to do with clause 3 of the regulations:
Third, aircraft flying in the East China Sea Air Defense Identification Zone should follow the instructions of the administrative organ of the East China Sea Air Defense Identification Zone or the unit authorized by the organ. China's armed forces will adopt defensive emergency measures to respond to aircraft that do not cooperate in the identification or refuse to follow the instructions.
The United States is not in the business of following instructions of the PRC when it does whatever it does outside of Chinese airspace.
Recall (well, maybe you don't recall, but it's what happened) that the "free navigation of the South China Seas" campaign of Secretary Clinton in 2010 was not an expression of her sedulous concern for merchant shipping; it was because the PRC had displayed the temerity to challenge, both practically and legally, the cruises of US Navy contractor survey vessels in the South China Sea.
On the short list of things that the United States is not going to want to do is have its aircraft obey some PRC ADIZ guy when all we want to do is chunk an aircraft carrier in the East China Sea and fly planes off it whenever and wherever we want.
My guess is, the US is punishing the PRC for its presumption (especially in not consulting with the US ahead of time) by allowing the issue to play out as "China goes aggro on the Senkakus" and giving aid and comfort to Japan.