Two "unarmed" US B-52 bombers, on a "long-planned" "training mission", made an "over-flight" through China's East China Sea Air Defense Identification Zone on Tuesday, according to the Pentagon.

On one hand, the White House and Pentagon have been trying to give the impression that they do not want to be overly provocative. On the other hand, they were anxious to send a message to intimidate.

That the Chinese military did not respond with defensive emergency measures may in part be because it is too accustomed to similar US military aircraft approaches in the same airspace to make a fuss. But, more importantly, it is an outcome of the country's consistent policy of avoiding avoidable conflicts.