Most Taiwanese don't consider themselves to be Chinese but I get your point. Yes it's true is most Asian countries but that's because they tend to be very racially homogenous and anyone who is not part of said group is a foreigner.
In Hong Kong, for example, every Caucasian is a gweilo (lit. ghost guy).
well since race is mostly a western construct, I suppose you mean most Asians are racially Asian. But I'm really not so sure that you can say Asia is very homogenous, culturally, ethnically, or genetically. Indeed, the issue wrt being Chinese is that the history of China is one of a enculturation into Chinese culture of a diverse set of groups throughout the mainland... where being Chinese is about acting Chinese more than it is about genetic and geographical roots.
I meant that individual Asian countries (especially in East Asia) are usually homogenous e.g. most people in Japan are Japanese, Korea Korean, China Chinese etc. So much so that often race and nationality are conflated.
In Hong Kong, for example, every Caucasian is a gweilo (lit. ghost guy).