Is Beijing's latest move in the East China Sea merely a bluffing game? Or is it ready to shoot down any "unidentified" planes flying over its freshly established air defence identification zone (ADIZ)?
Despite Beijing's warning that all planes passing through its newly designated ADIZ must provide their flight plans and maintain radio contact, the US has disclosed emphatically that two of its B-52 bombers - unarmed - passed through the area earlier this week without following the rules of the Chinese game.
It was a demonstration of open support for Japan, whose sovereignty dispute with China over the Diaoyutai Islands in the area is clearly the underlying cause of the latest tensions. It also comes as both a warning and protest against China's escalating regional tensions.
The US move may not be further taken to mean that Washington does recognise Tokyo as the rightful owner of what Japanese call the Senkaku Islands, but it is definitely a show of confidence that China would not dare take the "emergency" measures that it has vowed to take against planes violating the ADIZ.
Beijing has yet to respond to the US "provocation," but we can speculate about what steps China may take next by looking at the recent history of cross-strait tensions.
In 1996, when the pro-independence President Lee Teng-hui was running for re-election in Taiwan's first-ever popular presidential vote, China announced it would conduct a missile drill in the East China Sea - a move obviously intended to intimidate Taiwanese voters into shunning Lee.
Cross-strait tensions ran high and many Taiwanese people - and many in the international community - feared that military conflicts were on the verge of breaking out.
In response, the US Navy sent an aircraft carrier battle group to the area and the fleet reportedly passed through the Taiwan Strait as a deterrent to China taking military actions.
China did not back down - not completely. It still fired missiles into waters near Taiwan, but according to Lee, they were "dumb" ones, meaning they did not carry warheads.
China meant to deter Taiwanese voters from re-electing Lee, but inadvertently united them and gave him a landslide victory.
But does that mean China failed to achieve anything with that missile threat?