That's where you thought wrong...
since the inception of flight, nations try to finish war with air power alone, and from the last 100 years, we see a 100% failure (Well, unless you count the dropping of 2 atomic bomb is an "Air War")
History told us, in the following battle
Battle of Britain
Battle of Midway
Air War over Japan
Mig Alley in Korean War
Operation Rolling thunder in Vietnam War
Operation Line Backer in Vietnam War
Operation Desert Strom in Iraq
No Fly Zone in the Balkan
That air war alone cannot win the war for the country. And you are talking about massive destruction not just a few air sortie.
If you want to defeat japan, a ground war must be done, back in WW2, japan were bombed 24 hours a day and 7 days a week, more than 60% of ALL JAPAN were destroyed, up to 1.5 million Japanese Resident dead, yet they keep on pressing the war in the Pacific. You can try to destroy the Japanese Air Power and Sea power and bomb them day and night (which China still lack this capacity) and you can try and see if Japan surrender. You do know they won't surrender when we hit 2000 sortie per month back in WW2 with every B-29 Strike deal more damage than a single DF-21D warhead can do. Do you really think oh, we lob 100 or 200 DF-21D to japan and destroy maybe 150 military target (Giving the work rate is 75%, very generous) and they will simply surrender??
Not to mention the moment China and Japan have a fight, they will fortify the Island and put SAM there, barren does not mean undefendable. Then China are looking at a 3 dimension strike to incoming force.
Not to mention the distance between China and Senkaku and Japan to Senkaku. Every flight (sortie) made by Chinese from their Nearest airbase will be met with 2 flight of Japanese fighter launch from Ishigaki. The nearest airbase from China is Wenzhou, 330 Km away, where Ishigaki is just 170 Km away. In Air war, you are not talking about how many aircraft you get in your inventory, but how many sortie you can launch vs how many sortie the enemy can launch,
you cannot launch all 2000 aircraft in PLAAF Arsenal from Wenzhou base all at the same time....
And then there are naval ship, ok, let's assume China can actually destroy all of the Japanese Ship. Then what?? YOu want to enact an blockade in international water?? First, you need to ask yourselve this, after the engagement with JMSDF, would you still have enough ship to do such a blockade. As i can tell you this,
without a Naval Blockade, a naval victory mean nothing. Supply can still float in and out of Japan. Nothing is changed.
Then ask yourselves this, what happened if China actually stupid enough to start a naval blockade in international water?? It will piss off the World. Do remember senkaku dispute is a regional dispute, it's between China, ROC and Japan. Enact a blockade in international water will trouble everyone running across the region, Russia, South and North Korea and US to start with, do you think China can take all that heat from these country??
And that is all before US got involved. US can of course choose if or if not to involved, if they choose not to involve directly, they will still send secondary asset in international water and airspace and pipe down info for Japan for them to locate Chinese Target. US AWACS and NAVAL Intelligence ship do run around in international water. And Chinese cannot touch them unless they want to risk a total war with US. These kind of false flag operation we done it time and again, it's not something new.
Even if US decided to involve directly, they can send support ship to supplment the JMSDF, do remember if you claim it is just a Sea and Air war, then there will not be any nuclear exchange as 7th fleet alone with JMSDF can be more than take on the Chinese Fleet as of now. You do know Liaoning is not fully operational until 2015/2016 right? Not enough?? How about sending the 5th fleet along as well, now you got 4 aircraft carrier, 8 Guided Missile cruiser and 12 Destoryer in the US Force, with 30 destroyer and 20 frigate in JMSDF, more than a match to the whole PLAN fleet, which i doubt they would even muster up that kind of strength (No one will ever mobilse 100% naval power in a single threater, unless you want to get stab from behind.)
So all this, this is what Chinese looking at when they start a war with Japan, and when you start a war you better damn win it, otherwise your economy will set back a hundred mile, and Chinese government will become an international laughting stock.
If you are the Chinese Leader, would you want to go back to eat dirt or you want to fix your economy so you have sharkfin soup every day??
Hence a war can only happen in these forum member imagination, if you really want a war, go apply for a Japan vias and kill some japan defense personnel yourselve and see what your country will do for you??
If you are Putin, will you
1.) Sitting in you living room watching the whole thing expose and ready to sell Chinese some more ship and aircraft?? or
2.) Get your own hand dirty??
What do you think?? You do know Russia sell arms to Vietnam and India and South Korea too right, a war with their name on it in that region is not a good business. A war with country that buying their arms on that region, on the other hand is a very good business.
That is the exact same reason why US will not help out Japan much or even at all.