Trust USA not to have an opinion on anything; that will be the day! In any case, Japan and USA are in the midst of a missile defense deal and US Defense Secretary Leon Panetta is worried that China may take this deal in a different way and further aggravate the situation. Basically the US wants both the countries to stop provoking each other and sort the issue out amicably.
Foreign Minister Koichiro Gemba held a diplomatic meeting with Panetta, and confirmed that the disputed Senkaku islands are covered by a US-Japan security treaty. The said treaty was signed in 1960 and it states that USA is committed to aid the Japanese in the event of an attack on the nation’s territory. This contradicts USA’s previous claim that it will not takes sides in the island dispute. In the same breath, USA and Japan have signed a deal where USA will help Japan build a second missile defense radar installation on Japanese territory, aimed at countering North Korea.
The deployment of X-band missile defense radar in Japan is mainly to counter the threat posed by North Korea’s missile arsenal. This move will also help forward the deployed US forces and will be effective in protecting the US homeland from the North Korean ballistic missile threat. Currently there are around 47,000 US troops stationed in Japan and many of them are based on the southern island chain of Okinawa. Presently there is only one X-band radar at Shariki base in Tsugaru City, in the far north of the main island of Honshu.
Clearly this is more about North Korea than China, so Chinese friends, please take note!