Right around the time Captain America: Civil War hit theaters, a second superhero civil war started rolling through the comics. Civil War II centers on the young Inhuman, Ulysses, whose ability to predict the future comes to the immediate interest of the superhero community. Though the usefulness of his abilities is difficult to argue - Civil War II begins with multiple teams of superheroes saving the world by acting on information he provided - the extent to which they should be used begins to divide heroes, some of whom are focused on security, others on civil rights.
In 2006's Civil War, the Guardians of the Galaxy were keeping to the fringes of Marvel's story universe, but they've been a lot more prominent since a certain movie came out in 2014. And they have more reason to get involved in the Earth conflict of Civil War II than you might suspect.
Series writer Brian Michael Bendis has confirmed that the team of outer-space outlaws will spend some time stuck on Earth, putting some pressure on them to pick a side or risk getting caught in the crossfire. At the end of Civil War II #1, an old enemy of the Guardians and all life in general is also imprisoned on Earth - Thanos.
The Guardians team includes more Earthlings than it used to, imported from other Marvel titles: all the faces from the movie are still there, but so is the Thing from the Fantastic Four, Kitty Pryde from the X-Men, and Flash Thompson (a.k.a. Agent Venom) from Spider-Man's social circle. All of them, like Peter Quill, may be spending more time off Earth than on it, but they still have plenty of personal connections to the ol' homeworld through adventures in those other books. On the other hand, Drax, Gamora, Groot, Rocket and the other new arrival, Angela, are likely to have a more removed perspective on Terran affairs.
So far, Bendis is keeping his cards close to the vest about which side the Guardians will fall on. That seems deliberate. Civil War II already surprised some readers by putting Tony Stark on the "liberty" side, whereas in the first Civil War, he was on the "security" side. It seems likely that Marvel's spacefaring misfits, who have a long history of defying authority, wouldn't want to see law enforcement's reach stretch from punishing present-day crimes to punishing future ones (even highly likely future ones).
On the other hand, the group's not exactly Thanos' fan club, and Thanos was only imprisoned because of Ulysses' warnings. Complicating the group's loyalties further, the two major figureheads in this new civil war, Tony Stark and Carol Danvers, have both spent time in the Guardians' ranks, and Carol is now doing a fair amount of guarding the galaxy with her new team, the Ultimates. It's also possible that the Guardians, like the larger hero community, will split down the middle over the issue, at least for a while - team members turning on each other would hardly be a first for the group. A somewhat rotating membership opens up a lot more story possibilities, and that seems to be the way Bendis likes it.
Source: Comic Book Resources