This is an excellent article on the Senkaku Islands dispute.
China wants to wear out the Japanese ability and will to resist Chinese encroachment:
China's naval and paramilitary ships are churning up the ocean around islands it disputes with Tokyo in what experts say is a strategy to overwhelm the numerically inferior Japanese forces that must sail out to detect and track the flotillas.
A daily stream of bulletins announce ship deployments into the East China Sea, naval combat exercises, the launch of new warships and commentaries calling for resolute defense of Chinese territory.
"The operational goal in the East China Sea is to wear out the Japanese Maritime Self Defence Force and the Japan Coast Guard," said James Holmes, a maritime strategy expert at the Newport, Rhode Island U.S. Naval War College.
One problem is that the Chinese navy remains in the background while "civilian" agencies push the limits and throw elbows at the Chinese. One American naval officer put it well:
China's maritime surveillance agency, a civil proxy for the PLA, had become "a full-time maritime sovereignty harassment organization" with the goal of enforcing territorial claims.
If Japan uses their navy, it looks like "escalation."
If Japan stops reacting and resisting the Chinese moves, over time there will be a tipping point where Chinese authority is considered the status quo:
"If Beijing starts policing territory it claims as its own, and if rival claimants can't push back effectively, it will start looking like the rightful sovereign over that territory," said Holmes.
And until that happens, those bulletins trumpeting Chinese deployments have a nice secondary effect:
News of these missions also has domestic propaganda value for Beijing because it demonstrates the ruling Communist Party has the power and determination to defend what it insists has always been Chinese territory, political analysts said.
China also waves the bloody flag of World War II in order to pressure Japan and get other countries that have territorial disputes with Japan a reason to stay out of the way.
Japan needs to resist this pressure, unless they just want to give up. China is discovering that the Senkaku Islands are another "core interest" of China--an objective important enough to go to war over because China must have that objective:
Senior Chinese officials have strongly implied that Japan's claim over the islands is an attack on one of China's core interests, an important distinction to Beijing in defining its non-negotiable national priorities.
Which again raises the question of just what won't become a Chinese core interest? Because they keep mapping new claims. Increasingly, if China can reach it, they want it; and if they want it, it is a core interest.
So Japan can't fail to react or give China a toe hold. I say send in the robots to defend the Senkaku Islands.
Surface, sub-surface, aerial, and ground based robots (or remotely crewed devices, in the case of anything that can shoot) could be deployed around the Senkaku Islands. These robots would be defenders of Japanese control that will always be there, never tiring. And they could soak up every electronic and sound emission that the Chinese vessels release, for future reference.
Deploying coast guard or even navy vessels could be reserved for the most important messages.
Otherwise, let the Chinese play with the Roombas with attitude--they could transmit a message welcoming visitors to Japan and wishing them, "Have a nice visit!"
If the Japanese want to play a little rougher, like red-light camera systems, they could photograph intruding ships and planes and then send them a bill to the pilot or captain (sent to the unit) for the fee to visit Japan.
Armed robots for the really tough cases would be an option, too. With the Japanese Self Defense Forces in the background and the American armed forces on call, too.
China has already sent in robots (back to the article), after all:
There were signs that tension remained high last week when Tokyo protested that China had deployed a series of buoys around the islands to collect intelligence about Japanese operations.
China's Foreign Ministry said the buoys were in Chinese waters and positioned to collect weather information.
They just float and report, but they are robots. Japanese drones could destroy, disable, or retrieve those buoys. Japan could compete like this all day. Then the choice of destroying Japan's robot defenderss--while being filmed and recorded--would be a Chinese escalation choice.
Japan could also have export versions that would sell well to any nation within reach of China's military arm.
UPDATE: Obviously, I don't recommend the rock-shaped devices for any of the sea-based robots.