Mandatory Unretirement

A person who, after having given up his old job, is reluctantly forced back into work because he's just so damn good at it. Usually because his former colleagues have run into some desperate situation, and/or his replacements have failed. The opposite of Reluctant Retiree.

Often will be a police officer, soldier, or mercenary, but can be any job. Retired Gunfighter is a common starting point for this character, before they are forced into Mandatory Unretirement. Often set up as an extended Ten-Minute Retirement.

Anime and Manga

 * Full Metal Panic!: In the side story "Golden Days with Captain Amigo," Sousuke and Kurz both find million dollar treasure. And both are shown to be in agreement that, once they get rich from this, they would both hightail it out of Mithril and retire, doing what they want. However, after they accidentally destroy an M6 AS, the higher-ups from Mithril take all the treasure from them as payment. Incidentally, it's revealed that the executives estimated the cost of damages to be higher, thereby taking all the treasure and destroying both of their plans for retirement. Even more suspiciously, it's revealed that Kalinin had a hand in the expenses... and of course, Kalinin had showed numerous times his desire to keep Sousuke with him.
 * A recurring theme in Getter Robo is that if you piloted Getter at some point, no matter how far you run from it, destiny keeps throwing you in the cockpit.
 * At the end of the first season of Sailor Moon, Usagi wipes her and her friends' memories to give them yet another chance at a normal life without fighting. Come the second season, a new threat shows up and Luna is forced to restore her memories and reinstate her as Sailor Moon. Needless to say, Usagi is not pleased.
 * In Naruto, the Third Hokage is forced back into active duty after the incident that sealed the Kyuubi inside the main character- and the death of the 4th Hokage, obviously.
 * Kunieda Aoi of Beelzebub was the leader of the Red Tails, a gang of the strongest ladies of Kanto who Does Not Like Men, as such getting a boyfriend means that you quit. Kunieda sports an incredibly obvious crush on Oga since their first meeting and quits accordingly, however, the gang (and the Number Two especially) do not accept it and still treat Kunieda as their boss.

Comic books

 * Red: They should have left him alone.

Film

 * Unforgiven has the Retired Gunslinger variation.
 * Hudson Hawk. After getting out of jail, Eddie wants to go straight but various villains coerce him into becoming a cat burglar again because they need his expertise.
 * Hot Shots and Hot Shots! Part Deux. In both movies, Topper Harley quit the military, but the U.S. government sought him out and recruited him for a secret mission.
 * Our Man Flint and In Like Flint. In both movies, Z.O.W.I.E. chief Cramden must convince his reluctant old military subordinate Derek Flint to join up and save the day.
 * Blazing Saddles. The Waco Kid is a Retired Gunfighter who gives up his drunken ways and becomes a hero again to help his friend Sheriff Bart save the town of Rock Ridge.
 * Dreamscape. Alex Gardner gave up psychic research to use his incredible abilities to make money by betting on horse races. After being threatened by a bookie he rejoins his old mentor, who needs him for a project that has him entering the minds of sleeping people and sharing their dreams.
 * Flatliners. Brilliant student David Labraccio quits medical school after being forced to break the rules to save a patient's life. Although he's reluctant to do so, fellow student Nelson recruits him for a bizarre experiment to explore beyond the boundaries of life and death.
 * Blade Runner, Rick Deckard. Although
 * Swordfish, Stanley Jobson. although he was forced into "retirement" (convicted criminal) he is forced back into his criminal ways.
 * The Fifth Element: Korbin Dallas is a special forces soldier who gets called back into service for a mission after retiring and working as a cab driver. As per the trope he has no interest in the mission and only ends up agreeing to it because of a case of Always Save the Girl.
 * Mandatory Star Trek example: In Star Trek the Motion Picture, Kirk pulls a few strings and yanks McCoy out of retirement and back into his position as CMO, overruling and ending his objections with one memorable (and slashy) line: "I need you, Bones. I need you."
 * K in Men in Black II is yanked from his peaceful life as a mailman to join the MIB again due to knowledge even he doesn't know he possesses.
 * This is how Col. Jack O'Neill ends up involved in the events of Stargate, and becomes a recurring theme for him (see under Live Action TV below).
 * In Commando, the bad guys kidnap John Matrix's daughter in order to force him to do one last job for them. Big mistake.
 * Nick Charles in The Thin Man series of films gets pulled back into detective work after his retirement.
 * In The X Files: I Want to Believe, Scully works at a hospital and Mulder is still technically a wanted fugitive. The FBI recruits Scully to recruit Mulder (since she's the only one who knows where he is) to assist in investigating the X-Filean disappearence of another FBI agent. In exchange, all charges against Mulder are dropped and he's no longer a fugitive.
 * Mission Impossible 3 begins with Ethan Hunt retired from field duty and working only as an instructor, all ready to settle down and start a family.

Literature
"Councilor Pwoe: "I see now why Fey'lya never liked you, General. You should have been put out to pasture years ago." Wedge: "With All Due Respect, Councilor, I was. If you and the rest of the Senate had handled this war in anything approaching a competent fashion, I could have been left there.""
 * In the Night Angel books, Kylar tries to retire to a new city with his love interest, but since this happens in book two of a three part series, it obviously doesn't work. Both his friends and his enemies go to some considerable effort to pull him back in.
 * That's how Mackenzie Calhoun is pulled back into Starfleet (at least, the official Starfleet) in Star Trek: New Frontier. That, plus that fourth pip, plus Jean-Luc Picard saying "Get the groz in that Captain's chair, you idiot!" gets him fully back.
 * Happens again and again to Wedge Antilles in the Star Wars Expanded Universe. As early as the first-set issue of the X Wing Series he's been contemplating retirement and believing that there was too much he still needed to contribute. In the New Jedi Order, Legacy of the Force, and Fate of the Jedi he's been pulled out of retirement, because not only is he pretty much the greatest pilot alive, he's a skilled and inventive tactician.
 * Illustrative example from Rebel Dream:


 * George Smiley has retired at least three times and been brought back, albeit in an informal or advisory capacity, to clean up various messses made by his former colleagues in the security services. He does it enough that one character at the begining of Tinker, Taylor, Soldier, Spy insists, much to Smiley's chagrin, that his retirement (Smiley's second at that point) is merely cover.
 * Slughorn in Harry Potter and The Half Blood Prince.
 * In In Fury Born, retired members of the Imperial Cadre are technically only put on Inactive Reserve, meaning that the government can reactivate them if they want to.

Live Action TV

 * The Outer Limits TOS episode "The Chameleon''. When aliens land on Earth, government agents hunt down former secret agent Louis Mace because he's the best man for the job of infiltrating them.
 * Jack Bauer in spades. Went on indefinite leave after Season One due to, brought back in Season Two . Left (or, more accurately, ) CTU after Season Three, forced himself back into CTU from a Department of Defense desk job after CTU kept screwing up under new leadership in Season Four. , comes back in Season Five after . , is returned in Season Six to . Retired and just before Season Seven, whisked off by the FBI to help . Judging by the trailers of Season Eight, this is definitely happening again.
 * Gibbs "retires" at the end of Season 3 of NCIS. He's temporarily reinstated at the beginning of Season 4, and permanently reinstated by the end of the second episode.
 * Bizarrely, this is how Stargate SG-1 started: Col. Jack O'Neill had retired after the events of the movie, and they had to get him to un-retire for the series.
 * Happens several times to Thomas Magnum in Magnum, P.I. with the US Navy.
 * Tommy Oliver in Power Rangers Dino Thunder, back in the spandex after seven years off-duty, when all he wants to do now is be a science teacher. Notably, the only reason he has to unretire is because "science teacher" is his second idea of how to have a peaceful post-Ranger career, his first idea was "mad scientist". His mad science career was such a disaster he ended up becoming a ranger again just to clean up. He re-retires after that.

Professional Wrestling

 * Just about every 'retirement' ends up rescinded via this, usually with the retired guy having no other way to try and shut a young upstart up than to prove he's (still) as good as his reputation indicates.

Real Life

 * Many US military members were mandatorily called back into active duty on the start of the second Gulf War, in some cases because there was equipment being used that nobody knew how to maintain anymore.
 * In fact, this is a case of All in The Manual. The enlistment papers that you sign to join indicate that there is a period of time where you agree to be called back into duty according to the needs of the service. Usually your total commitment comes out to something like eight years total, including Active Duty, the Reserves, and the "Inactive Reserves" (the guys who get rudely yoinked back into duty.)
 * In theory, every able-bodied male who opted to register in the Selective Service (that's all able-bodied American males between the ages of 18 and 25) can be called into military duty, but any circumstances where that might actually happen could probably be considered Nightmare Fuel by themselves.
 * Officers are theoretically subject to recall indefinitely, and must keep two uniforms in case it happens.
 * Retired programmers were rehired en masse to fix older computer systems affected by the Y 2 K bug.
 * Imran Khan was called out of retirement to play for Pakistan in the 1992 Cricket world cup - Pakistan's president even compared it to a soldier being called on to fight for his country.
 * Gerd von Rundstedt was one of Germany's top field marshals during World War II. He had retired in 1938 after over forty years of service, only for Hitler to reinstate him to lead the Wehrmacht into Poland. In the summer of 1944, he was forcibly retired because he was "difficult to work with" (in truth, he called for much needed reinforcements to contain the Normandy landing, but he was overruled), and was then brought back again as the Western Front verged on total collapse. His timely arrival allowed the Germans to stabilize the front along their border, leading to the Battle of the Bulge.

Video Games

 * In Metal Gear Solid, Solid Snake is essentially kidnapped and blackmailed into starting the events of the game. Then it happens again in the fourth game. It's apparently genetic, as something similar happened to Big Boss to set off Portable Ops.
 * Descent II opens with Dravis informing the player character, Material Defender, that the contract he signed with PTMC allows them to retain his services for more missions; if he declines, he won't get paid for the work he's already done.
 * And as anyone who has seen the intro for Descent III knows, he can't get a break even after Dravis tries to kill him, as his rescuers (who are the good guys) use his desire for revenge to override his desire to just settle down somewhere nice and quiet.

Web Comics

 * In the Penny Arcade story "Paint The Line", Tycho and Gabe are forced out of retirement by the government. They're retired ping-pong players.