After the conclusion of World War II, the Taiwanese went from a colony of a foreign people to that of the same extraction. Because of the illusion of a "mother country," Taiwanese embraced and welcomed the Chinese troops wholeheartedly despite the slight disappointment at the shabby clothes and undisciplined conduct of the Chinese army. On the other hand, these Chinese did not consider Taiwanese their compatriots. Instead, they thought of themselves as victors in a conquered land, successors to the Japanese viceroy. They took on not only the colonial measures of economic exploitation but also all sorts of legislation that discriminated against the Taiwanese. Completely surprised by such unequal treatment, the Taiwanese felt disenchanted and shocked as their naive conception of the "mother country" proved utterly wrong. This disillusionment eventually led to the tragic 228 Massacre.
In essence, the 228 Massacre was quite similar to massacres in the early Japanese colonial rule for the fact that they all resulted from the colonizers' attempt to suppress resistance of the colonized. After 228, Taiwan was further dragged into the Chinese civil war which had nothing to do with Taiwan itself. In the end, Taiwan actually became a base for Generalissimo Chiang Kai-shek's plot to "take back the mainland." While the KMT's military attack to regain control of Mainland China never happened, Taiwan in the meantime has changed greatly. The KMT has exploited the land and the people of Taiwan: rampant deforestation continues as the land no longer holds water, illegal deals, bribes and embezzlement take place regularly between and among government employers and business people; the blacklist and so-called "white terror," etc. have not only violated human rights but also instigated fear and distrust in the heart of the Taiwanese.
By and large, international factors also contributed to the KMT occupation of Taiwan. The Cold War made it necessary for the United States and its allies to strike a balance of power to counter the USSR. In so doing, they chose to overlook the universal trend of independence movements in former colonies in the post war era. In the Peace Treaty of San Francisco, Japanese concession of Taiwan was made and yet the status of Taiwan was left open for debate. This ambiguity seemed to have embraced the idea of self-determination while leaving room for diplomatic maneuvers for Cold War strategy. In the end, the international world acquiesced and consented to the KMT regime's takeover of Taiwan as a result of the interplay of the Cold War and Red Scare engendered by McCarthyism in the US.
As the Cold War dragged on, the fact that Taiwan was under the KMT's colonial rule was forgotten. The reality of a Chinese rule seemed to have justified for the claim that Taiwan was part of China. Additionally, after China's breakup with the USSR in the fifties, the US and its allies strategically had to lure China for the balance of power. As a result, Taiwan again was a victim in the game played among the imperialistic powers.
Whereas the international world remains close with China and sometimes comes under China's dictating threat, some people, blinded by the propaganda of the KMT, deemed the KMT colonial pretension as a legitimate claim; they completely ignored the sovereignty of Taiwan. It was not until the failing of the KMT's diplomatic efforts in the seventies that this regime began implementing the policy of localization. However, while co-opting the Taiwanese elite into its system, the KMT still vehemently denied the right of self-determination for the people in Taiwan. The situation resembles the limited self-rule a colony would be permitted during the colonial period.
The Chinese policy of Chiang Ching-kuo insisting on "One China" has remained largely the same after Lee Teng-hui succeeded Chiang. "The Guidelines for the Unification of China" (kuo tung kang ling) best illustrates this point. This document was drafted without consultation with Taiwanese society at large or the endorsement of the Taiwanese. Although emphasizing flexible, pragmatic objectives for different stages, it presupposes the ultimate goal of unification. Moreover, KMT considers Taiwan a tool for China's achieving "democracy, liberty and equality." The exploitative, colonial policy certainly cannot be accepted by any sensible Taiwanese.
Constitutionally or administratively, Taiwan during the forty something years of KMT rule is fundamentally a colony. Realpolitik in the international world and self-desertion of some Taiwanese have justified the KMT regime on Taiwan while consenting to the PRC's claim of authority in and ownership of Taiwan. However, no foreign governments or regimes should ever be allowed to seize the sovereignty of Taiwan.