For Japan, investigating a fishing vessel trespassing in areas under its administration (which was what precipitated the crisis) would seem appropriate, as does its reaction when its orders are resisted. Yet the reported decision to release the captain without trial seems to undermine this position. More to the point, Japan’s response is likely to teach Beijing that if it blusters and shouts sufficiently, it will get its way. By failing to hold to their principles, Japanese officials should brace themselves for further such incursions and ever more assertive Chinese stances.
Not that Japan needed to match China in over-the-top rhetoric, but releasing the captain after judicial proceedings were completed might have been better.
Nobody wants this dispute to go to war. And it won't. But if Japan becomes viewed by China as an easy target (and doesn't believe America will back Japan), Japan could find themselves compelled to respond to a future crisis with military force or threats of force in an effort to keep their reputation from sliding further.
We faced that problem back in 1975 after South Vietnam fell and the Cambodians seized our merchant ship Mayaguez:
When the merchant ship Mayaguez and its American crew were seized by communist forces off the coast of Cambodia in 1975, the Ford administration was determined to craft a muscular response in hope of limiting damage to U.S. prestige, according to newly declassified documents published by the State Department.
I won't pretend that it is easy to navigate between cooling off a crisis so it doesn't lead to war and defending one's reputation, but that is why nation's have large corps of professional diplomats, right?