Modern history of East Asian martial arts
Taekwondo was developed from karate for use in the Republic of Korea Armed Forces from 1954. For this purpose, karate terminology needed to be "nationalized". The name "taekwondo" is due to shotokan practitioner and army general Choi Hong Hi. After the Korean War, Taekwondo was further developed into a purely sportive discipline, since 1973 overseen by the World Taekwondo Federation. 
During 1964-1966, Choi Hong Hi continued to promote taekwondo, working to put together a world-class exhibition team. Taekwondo's emphasis on jumping and flying kicks dates to this period. While taekwondo was based off karate, the structural changes made in the 1950s and 1960s were significant, and it cannot now be considered a branch of karate, but is a standalone modern martial art. Taekwondo was presented at the Summer Olympics as a demonstration sport in 1988 and 1992, and became an official Olympic discipline in 2000.
Ki Ha Rhee
When Rhee served in the South Korean military forces, he came into contact with Choi Hong Hi and learned taekwondo in the 35th Infantry Division. Rhee was a key figure in the introduction of taekwondo across the world, contributing to demonstrations in many different countries. He later taught taekwondo to the US 8th Army and, in 1964, travelled to Singapore, where he trained Royal Air Force (RAF) personnel at RAF Changi. Through the late 1960s and 1970s, Rhee was a key member of the taekwondo demonstration teams that accompanied H. H. Choi around the world.