If you want specifics with sources and foot notes I suggest "A killing Art" . Also, Gneral Choi's 1965 Book where the Shorin and Shorei roots common to Shotokan and the Shotokan connection is clearly stated.
Briefly, Pres, Rhee of South Korea was so impressed by a demonstartaion which was part of a Military demonstration in 1953 or 1954, performed by a group largely composed of Chung Do Kwan members (Including Han Cha Kyo and Nam Tae Hi) doing a Korean flavored Shotokan, That he ordered General Choi to teach the stuff in the Military. Toward that end General Choi formed the 29th infantry division and recruited the top Matial art talent. This division formed the Oh Do Kwan, gym of my way or gym for all of us so varous Kwan members could all be a part of the new gym as a collaborative effort rather than be viewed as joining the competion.
As part of the process needed to teach on a wide scale, techniques and rank from the various systems needed to be standardized as did the name Tae Kwon Do (Adopted in 1955), later Taekwon-Do which also eliminated the Japanese name and prior Kwan connection.
Government and Military resources were used to demonstrate and teach as well as dispatch instructors throoghout the world, as well as recruit outside instructors such as Jhoon Rhee for the unified system.
Political influence and resources worked amazingly well for Gneral Choi until he became persona non grata and / or refused to allow the government to control TKD at which time he left South Korea taking TKD with him onky to have the Government uses it's resources to influence instructors to leave him and develop a new system it called Taekwondo. (1973 or so)
The government used it's resources to train train and recruit instructors and spread TKD. The success of the spread speaks fr itself.