A hub and spokes architecture is an information architecture that follows principles from the spoke-hub distribution paradigm. In particular, it has evolved as a best practice standardization method for data warehouses. Data is collected, cleansed and versioned from several data sources into a central hub - the data warehouse - from which business application specific data marts can be derived.
The "Hub and Spokes" architecture (or the San Francisco System) is a network of bilateral alliance (bilateralism) pursued by the United States in East Asia, after the end of the World War II. Hub and spokes system allowed the United States to develop exclusive postwar relationships with the Republic of Korea (ROK), the Republic of China (ROC or Taiwan), and Japan. These treaties are an example of bilateral collective defense. Since the system emerged under the U.S powerplay rationale, it is the most dominant security architecture in East Asia up to now.
Hub-and-spokes system, with the United States as the "hub" and no apparent connections between the "spokes" allowed the U.S to exercise effective control over the smaller allies of the East Asia. The legacy of the system is continuing until today, represented by the absence of the multilateral security architecture(multilateralism) in the region like NATO.
Right after World War II United States was not interested in being involved in East Asia and was more concentrated in its role in Europe. However after Pearl Harbor and the Korean Conflict, the US became more engaged in North East Asia.
The US started building its bilateral relations in East Asia with Japan. At the San Francisco Conference in September 1951 the US signed the US-Japan treaty of Mutual Cooperation and Security. Later on it moved to sign a Mutual Defenses Treaty with the Philippines in August 1951, the US-Republic of Korea Defense treaty with Republic of Korea in October 1953, the 1954 Mutual Defense Treaty with Taiwan, and the US-Republic of China security treaty with China in December 1954. With these treaties the US was able to construct the Hub and Spokes System.
Victor Cha explains the reason for the US’s choice for a bilateral structure with the powerplay theory. The underlying idea came from the Domino Theory- that if one nation falls into communism others will follow. He defines powerplay as 'the construction of an asymmetric alliance designed to exert maximum control over the smaller allies in the region that might engage in aggressive behavior against adversaries that could entrap the United States into an unwanted war.' In other words, the hub and spokes system allowed the United States to not only contain the Soviet threat but also have exclusive power over the East Asia. With this system the US would be able to control of the rogue allies (rogue state) - anticommunist dictators who might start wars for reasons for domestic legitimacy (political) of their own regime. The US had a fear that it may be entrapped in an unwanted war, thus needed a way to contain these rouge allies. An example of a rouge ally is Syngman Rhee of South Korea. Due to his ambitions to unify the Korean peninsula, the treaty would contain his adventurism. Another is Chiang Kai-Shek. His ambition to overtake mainland China heightened the fear of entrapment to the US.
Hub and spokes system is highly asymmetric alliance in nature. The system can best be explained through the lens of security-autonomy tradeoff model. The model accounts for asymmetrical alliance ties involving states of different power status than for symmetric alliance bonds. Asymmetric alliance is a contract which a major power takes on the responsibility for minor country's security by pleading to support it in the contingency of military conflict. In return, major power gains autonomy or influence over the minor power's foreign policy decision-making process.
The rationale for the spokes to entering this system can be explained as minor powers may seeking alliances in order to increase security from military aggression. While major powers may be interested in alliances with minor powers, not to defend its own territory, but to extend their sphere of military and foreign influence.
It is important to note that the nature of the relationship was a bit different with Japan from other East Asian countries. The US viewed Japan as a possible great power in East Asia. Thus, the US constructed the strongest defense treaty with Japan. The US wanted Japan to be more involved and share the burden in peace keeping in Asia. However, the Yoshida Doctrine shows that Japan did not share the same ideas.