There is roughly a 9 year gap between the events of TMP and WOK. What were the crew up to in the decade between the two films? Why did Kirk leave his command again after having lobbied hard to get it back during TMP?
Back to the topic, the book The Autobiography of James T Kirk gives the following explanation of what happened between TMP & TWOK:
Christopher Pike is promoted to Fleet Captain - a rank he considers to be given to officers that Starfleet want to promote out of the way of any real decision making.
Kirk takes command of the Enterprise
5 Year Mission commences
Enterprise is recalled to Earth prior to the end of the 5YM, Kirk is offered promotion and a job on Nogura's staff
Spock requests a leave of absence to pursue Kholinar
Kirk offers XO to Decker with a view to taking over captaincy
Enterprise returns home after the 5YM
Enterprise is refit, Kirk is very involved, including crew selection
Kirk also notices some irregular and illegal build up of munitions against the treaty with the Klingons, and traces this back to Nogura
V'ger rocks up
Kirk asks for command of the newly refitted Enterprise
Nogura says No
Kirk mentions the munitions
Nogura gives him the Enterprise
Kirk sorts out V'ger
Kirk takes the Enterprise on a second 5YM
Nogura carefully removes any evidence left by his wrongdoing during Kirk's absence
Checkov transfers to the Reliant as XO due to lack of the availability to advance under Kirk (All command crew in place an not going anywhere anytime soon)
Enterprise returns home after its second 5YM
Nogura promotes Kirk to Fleet Captain, promotes Spock to captain, and insists that any officer who served under Kirk can only leave the ship by resigning from Starfleet. This is Nogura's revenge for Kirks blackmail 5 years earlier - Kirk immediately resigns from Starfleet
Spock takes the Enterprise on a 3rd 5YM
Kirk meets and shacks up with Antonia
Nogura is drummed out of Starfleet. Adm.Morrow is promoted to CinC
Morrow asks Kirk to come back to Starfleet as an Adm.
Kirk assigned to the academy
TWOK
What do you think? I quite liked how Kirks gung ho actions to get the Enterprise back had serious long term consequences