If you want something a bit theory-y and from a somewhat (non-Western) Marxist perspective, Chen Kuan-hsing's Asia As Method: Toward Deimperialization is pretty good. Chapters 1 and 4 are probably some of the best takes I've seen on Taiwan in terms of its place in US imperialism and in terms of the US-Cold War mentality that still dominates Taiwan's political culture — it was written in the early 2010s but it rings exceptionally true in light of 2020, when many of Taiwan's seemingly succdem political factions turned full Trumpian.

One shortcoming of Chen's book is that it does not at all critique the blatant settler colonialism in Taiwan independence movements and Taiwan nationalism today. But I can't think of an English text I've read that unpacks the Indigenous struggles in Taiwan's history very well (there's this book Taiwan's Imagined Geography: Chinese Colonial Travel Writing and Pictures, 1683-1895 by Emma Jinhua Teng, published by Harvard, but it's a standard academic history of Han Chinese settlements in Taiwan in the 17th-19th centuries, and it's pretty lib and quite settler-centered in perspective).