OK with regard to Tony and DB's last posts...
I agree it is circular. Let me restate that: Taekwondo, both as it was founded in the 50's, and as it exists now, was and is Korean. It is what the Koreans say it is, even if the rest of the world wants it to be something else. Which they frequently seem to want.
It's difficult to understand and apply the essence of the martial art without understanding concepts like Do, Taegeuk, Samjae, Um-Yang, Kang-Yu and Yeokhak, for example. If you didn't grow up with them, in order to understand these concepts even at a rudimentary level, it is necessary to view them in their wider contexts, ie Taoism, Buddhism, Confucianism, their relationship with Samilshingo and the Chunbukyeong, and the Han philosophy. All of this is built into the forms and motions of Taekwondo, along with historical symbolism.
Now you can take the combatives out of Taekwondo and go and use and develop them for sport, or to fight, as many countries have done, but the core of the martial art will not come with them. You can practice the forms as empty placeholders too, maybe even gain some insight from repetition, but without the wider context, a lot of the information in there goes right over our heads with a nice wooshing sound. That's less likely to be the case with a Korean native.