In Captain Marvel, it's explained why there were no alien invaders on Earth before Thanos (Josh Brolin) made his move with the help of Loki (Tom Hiddleston) in Joss Whedon's The Avengers. On top of officially introducing Brie Larson's Carol Danvers, the latest MCU movie also offers the intriguing reveal that Ronan the Accuser (Lee Pace) was interested in the Tesseract long before he turned his attention to the Power Stone in Guardians of the Galaxy.
Set in 1995, Captain Marvel takes audiences back in time to when young S.H.I.E.L.D. operatives Nick Fury (Samuel L. Jackson) and Phil Coulson (Clark Gregg) first encountered Danvers. Unaware of her past on Earth, Captain Marvel is going by the name Vers (taken from a fragment of her dog tags). After slowly regaining her memories and realizing that the Kree are the real bad guys, she switched sides with the Skrulls, assisting them in escaping her old allies. As Captain Marvel easily obliterated Starforce, Ronan watched quietly on the sidelines. Initially wanting to join the battle, he retreated after seeing her fully unleashed powers in action - but not without the promise that he'll return for her.
Despite his threat, Ronan never returned (at least that we know of) to Earth, and neither did the power-hungry Kree attempt to add the planet to their vast empire. Ronan was taken aback by how powerful Carol is upon seeing her easily fending off the bombs he unleashed on Earth. Following that impressive display, Captain Marvel sent Ronan an unspoken warning to cease the attack - or else. After this conflict, news of a powerful hero protecting Planet C-53 may have spread across the galaxy, discouraging any extraterrestrial race from attempting a hostile takeover.
This effectively explains why Earth was safe from any space invasion for years. Since the events of Captain Marvel, there weren't any attempts to take over the planet until Loki's (failed) efforts in The Avengers. Knowing that the Space Stone/Tesseract was on the planet, Thanos tried to make a move on Earth. However, even at that point, the Mad Titan didn't do it himself, opting to send a proxy instead in a Mind Stone-equipped Loki. Unfortunately for them, while Carol wasn't around to take care of the God of Mischief and his Chitauri army, Fury was able to successfully assemble Earth's Mightiest Heroes as part of the Avengers Initiative - which, we now know, was inspired by his experiences with Captain Marvel.
Now that Carol is back on Earth following Thanos' Decimation, she joins the team of superheroes who took their name from her Air Force call sign. She's expected to play a pivotal role in the upcoming battle against the Mad Titan, but whether or not she stays back in Earth for good following this current debacle remains to be seen. There's still a lot we don't know about her story between the time she joined the Skrulls to help them find a permanent home planet in Captain Marvel and her eventual return two decades later, and the sequel can easily explore that time. But assuming she decides to stay grounded moving forward, her presence may well keep Earth some from future invaders.
- Captain Marvel (2019) release date: Mar 08, 2019
- The Avengers 4 / Avengers: Endgame (2019) release date: Apr 26, 2019
- Spider-Man: Far From Home (2019) release date: Jul 02, 2019