Theoretical explanations of the period of peace between Japan and the USA (from 1945 onwards)

On the 7th of December 1941, Japanese submarines and carrier-based planes attacked the U.S. Pacific fleet at Pearl Harbor, killing 3000 military personnel, and destroying a great part of the fleet. This led to a 4-years war culminating in Hiroshima and Nagasaki, a milestone in human history. Japan was defeated for the first time in its history and occupied by foreigners, imposing their culture and values. Fifty years later, the same country has become one of the three major economic power, creating a brand-new growth model, has experienced years of political democratic stability and has never ceased to cultivate its independence and cultural specificity. Therefore, the country remains surprisingly neutral when it comes to international politics, which is the main reason why common wisdom has it that Japan is both an economic giant and a political waif. Only on this precise point does a strong dependence to the U.S. remain obvious, as Japanese diplomacy merely reflects and follows American positions.

[...] This overthrow of the SJP’s political doctrine became official on May 27th 1995 when a new declaration, recognizing the constitutionality of the self-defense forces, the importance of the peace and security treaty and the constitutionality of the 1992 Peace Keeping Operation law, was adopted. This goes to show that when they come into power, politicians are compelled to think and act in terms of their national interest. This national interest is according to realists, given once and for all, may it be defined as security, power or the spread of ideological preferences. [...]

[...] On November 9th 1990, the rupture between the former allies had become clear as the JSP still refused any kind of military intervention while the Komeito and the SDP supported the project of the government that planned to enable a few small units to take part in peacekeeping operations for the United Nations on the condition that the self-defense forces wouldn’t take part in them. It authorized the dispatch of Japanese troops abroad for the first time since World War II. [...]

[...] On the other hand, Gilpin’s power-cycle theory seems somehow more satisfying to explain the absence of war between Japan and the USA and their renewed alliance. After its forced opening to the outside world and the Meiji revolution, Japan began to look for its rightful place in the international system. At the very beginning it seemed content enough with following the lead of the then-hegemonic power, namely Great Britain. It was a minor but satisfied power co-opted into the British hegemony. [...]