What China poses to Japan is more of an opportunity than a threat. Let's face it, the island and maritime dispute have no chance to break a war between two trade booming and economily flourishing neighbours. China has absolute no intention to invade Japan, and I dont think Japan wants to wage a war to a nuclear armed and militarily rising China. I suspect Mr. Abe is using China as an excuse to release the strains posed by US after WWII. Although political relationship and national sentiment between the two is tensed, there's no actual provocative activity from PLA nor from JSDF. On the other hand, Mr. Abe put forward many strategies to"cope with China threat", yet his real move was to strive for as many independency as he can for Japan. I think the US gov may not view Mr. Abe as an obediant ally privately, and once Japan could ever get rid of US grip, Japan will turn more neutrual between US and China or maybe even sort of "pro China" in US eyes, and the US will not be happy with that then they'll try everything to keep Japan in hand and aviod any major political concession, so they will just stir up sensitive issiues and pull the string, make subtle and vague promise yet fulfil them half-heartedly.
You are very sharp, my friend! Are you specialized in East Asian policy ?
During this time, around the early to mid 1950s, your country's greatest statesman, Zhou Enlai, once appraised on the imposition of the 1951 Washington-Tokyo Treaty of Mutual Defense as one that posed a threat to Japanese security and national independence and had no qualms about appealing to Japanese nationalist sentiment in support of his positions.
In fact, Zhou said that the PRC leadership understood that the peace and security treaties had been forced upon Japan by the United States in cooperation with a "traitorous" group of reactionaries in the Japanese government who had put the Japanese in the "unprecedented national danger (minzoku kiki)" of being involved in another war of aggression by "shamelessly selling out the state's independence and sovereignty."
Zhou's appeal to Japanese nationalist sentiment was a carefully targetted rhetorical strategy. In a conversation with Yoshida , Zhou once told him , and Yoshida would write about it in his journals, about how the security treaty seemed to be a continuation of the American occupation and included the danger of involving the Japanese nation in another self destructive war with the Soviets (which were the threat at the time).
It seems that during that time, there were factions in the LDP who were in the position of Japan forming a strategic security pact with PRC. In fact this was actually the direction of policy from 1960s all the way up to the late 1970s. This would change with the Reagan administration in the early 1980s.
In other words, buddy, Japan is not "100% Pro America", only a naive fool would think so. Japan sees America as a threat to national sovereignty, more than Chinese, actually. The predicament we are in is having to change constitutional legislative laws that have been set in place (ironically it was written by Americans) since the end of the war , which had severely limited Japan's foreign policy abilities.
In other words, the proverbial "chain" America has on Japan is historical. A means to control the "vanquished" enemy, Imperial Japan, from being a threat to American Pacific Hegemony.
Oh , did i say it so directly? lol. I suppose i did.