"Civil War" is a 2006–07 Marvel Comics crossover storyline consisting of a seven-issue limited series of the same name written by Mark Millar and penciled by Steve McNiven and various tie-in books. The storyline builds upon events in previous Marvel storylines, particularly "Avengers Disassembled", "House of M", and "Decimation". The series' tagline is "Whose Side Are You On?" The plot begins when the U.S. government passes a Superhero Registration Act, ostensibly to have super-powered individuals act under official regulation, somewhat akin to law enforcement. Superheroes who oppose the act, led by Captain America, find themselves in conflict with its supporters, led by Iron Man. Spider-Man is caught in the middle, while the X-Men take a neutral stance. The superheroes who support the law, including Mister Fantastic and Ms. Marvel, become increasingly authoritarian. Civil War explores the conflict between freedom and security against a backdrop of real-life events and discussions, such as the U.S. government's increased surveillance of its citizens. The series polarized critics and fans but it was a commercial success. A sequel, Civil War II, debuted in June 2016. The 2016 film Captain America: Civil War in the Marvel Cinematic Universe loosely adapted the storyline. Publication history The Superhero Registration Act introduced in Civil War requires any person in the United States with superhuman abilities to register with the federal government as a "human weapon of mass destruction," reveal their true identity to the authorities, and undergo training. Those who register may work for S.H.I.E.L.D., earning a salary and benefits like other American civil servants. Characters within the superhero community in the Marvel Universe split into two groups: one advocating the registration as a responsible obligation, and the other opposing the law on the grounds that it violates civil liberties and the protection that secret identities provide. While arguing with Iron Man about the law, Luke Cage (previously the second Power Man), an African American, compares the mandatory registration to slavery. A number of villains also choose one side or the other. Mark Millar, writer for the story, has said: Delays Marvel announced in August 2006 that some issues of the main Civil War series would be pushed back several months to accommodate artist Steve McNiven. The schedule had issue #4 being released one month late, in September, while issue #5 was released two months later, in November. Furthermore, various tie-in books including the Civil War: Front Line miniseries