A common criticism of the Marvel Cinematic Universe is that each film only exists to set up the next. It's an unfair one, in my eyes; for the most part, the films of the Marvel Cinematic Universe are in the habit of reacting that which came before more than than they are setting up future ones, something that helps make this constantly evolving world feel incredibly natural. Yes, Avengers: Age of Ultron can only happen thanks to the events of Avengers Assemble and Captain America: The Winter Soldier, but it never feels like those films only happened so that Avengers: Age of Ultron could. It's a careful balancing act that Marvel Studios haven't always pulled off, but when it works it works wonders.
As such, Captain America: Civil War is a reaction to... well, a lot. The world has grown weary of the Avengers since Sokovia fell out of the sky in Avengers: Age of Ultron, and after another Avengers mission results in civilian casualties an international agreement called The Sokovia Accords is created to stop the Avengers from operating without oversight from the United Nations. Those that sign the Accords can continue to work as an Avenger under the UN, but those that don't - such as Steve Rogers - have no legal right to involve themselves in those kind of conflicts; something that becomes a big issue when a still in-hiding Bucky Barnes is becomes the primary suspect behind a terrorist attack.
For those paying attention, Captain America: Civil War is effectively the pay-off to various stories and character arcs that have been established and developed over the last 8 years, offering definitive proof that that the notion of a shared cinematic universe has a lot to offer when it comes to long-form storytelling. Steve and Tony's divide over the Accords is one rooted in who they've become after multiple films worth of character development, and the stance they each take is exactly the one fans will expect. Tony, driven by the guilt he feels over the creation of Ultron, is in full support of the Accords; Steve, driven by his distrust of bureaucracy in the wake of the fall of SHIELD, is firmly against it.
It's a conflict rooted in well-established ideologies and reinforced by reasons personal to the characters, an important part of why the escalation of disagreement to argument to a full-blown fight feels not just natural, but inevitable. And the same is true of the rest of the characters that choose a side in Captain America: Civil War; although they aren't the focus of the film, they still all have a clear reason for choosing the side they choose, only adding further weight to an already hefty divide. This isn't just another brief tiff between Tony and Steve, this is the Avengers torn asunder, and there are real, immediate consequences for everyone involved. Anyone who is concerned that Captain America: Civil War will simply end with a return to the status quo (not that these films have ever had a status quo) can rest at ease; I'll be very surprised if the events of this film don't end up shaping the rest of Phase 3.
Not that Captain America: Civil War is all doom and gloom. While it's true that this is quite easily the darkest film in the Marvel Cinematic Universe so far, the Russo Brothers are smart enough to ensure that the tone never becomes stale by littering the film with the same kind of organic humour that we saw in Captain America: The Winter Soldier. There are some very vocal people on the Internet who insist that these films are too focused on comedy, but these people are idiots and should be ignored at all costs; nothing makes a dark moment more effective than when it is contrasted with a lighter one, and the Russo Brothers' understanding of that is a large part of how they manage to balance the tone in a film that spends a lot of time in some emotionally heavy places.
The other way they balance tone is by sticking the most vibrant, fun, comic book-y action scene we've ever seen directly in the middle of the movie. The airport sequence you've seen in trailers is quite simply spectacular, a super-powered brawl that sees Team Cap and Team Iron Man clash in the most imaginative and ridiculously fun way possible. Anyone concerned about the Russo Brother's ability to deal with the more fantastical power set of some characters can rest at ease; based on this, the upcoming Avengers: Infinity War two-parter is going to be nothing short of a visual extravaganza. And don't get me wrong, Captain America: Civil War still contains plenty of the grounded, hand-to-hand action sequences that helped made Captain America: The Winter Soldier as great as it is, but they aren't what you'll be talking about on the way home. You'll be talking about the one where Hawkeye shoots an arrow with Ant-Man riding on it.
Any issues I initially had with Captain America: Civil War were alleviated by a second viewing, which revealed a lot of what I thought were structural issues to instead be a side-effect of the subtle misdirection that the Russo Brothers are employing throughout. There is a lot to take in on first viewing thanks to how ambitious a film it is, but knowing what to expect in advance proves Captain America: Civil War to be deceptively tight, a movie where the only bit of fat comes from the introduction of Peter Parker into this universe; and when something is so immediately and obviously worth the small diversion (on top of being a brilliant scene in it's own right), you really can't complain.
And Tom Holland's Peter Parker (who is already the best live action version of the character we've ever seen, by the way) is just one of the new and instantly captivating characters that Captain America: Civil War introduces us to. Chadwick Boseman is fantastic as T'Challa, instilling the character with the nobility, dignity, intelligence and physicality that he requires with ease; Marvel Studios seem to be hoping that Black Panther will be their next big hero, and they've certainly ensured that he's off to a great start by getting the character so, so right. And it's also worth mentioning that despite the common complaint that the films in the Marvel Cinematic Universe have weak villains (something I disagree with), Daniel Brühl is simply mesmerising as Helmut Zemo, maybe the best Marvel antagonist we've seen on the big screen since... well, Loki.
It might take a second viewing to really appreciate what Captain America: Civil War is doing, but that doesn't make what the Russo Brothers have achieved here any less impressive, pushing the boundaries of the superhero film while also delivering one the best the genre has ever produced. Captain America: Civil War is ultimately nothing less than a great film, thematically rich and emotionally complex without losing the adventure and sense of fun that has made the Marvel Cinematic Universe as successful - both critically and commercially - as it is. In short, it's yet another reminder of how good blockbuster entertainment can be from a studio that have been redefining the way we watch movies for the best part of a decade, and I'm glad to see that Marvel Studios show no sign of stopping now.