Despite what Marvel Studios might have you think, there's a lot more to Captain America: Civil War than the conflict between Captain America and Iron Man. A huge subplot in the film concerns the Black Panther and, more to the point, Vibranium. If you've been paying attention to previous Marvel movies, then you've likely heard this word before. Vibranium has been mentioned in more than a few films in the Marvel Cinematic Universe (MCU), but it has picked up steam recently, even enjoying its own minor subplot in Avengers: Age of Ultron. But just what is vibranium, and what does it have to do with Civil War?
Vibranium is a malleable, strong, and very rare metal probably best known as the impenetrable metal Cap's shield is made out of. The shield Cap uses as a fierce, crime-busting frisbee is lightweight (well, for him) and thin, but also incredibly durable (Thor has hit it with his hammer without even leaving a dent). Unfortunately, when Howard Stark made Cap's shield, he used up all the vibranium he had, and the metal hasn't gotten easier to find in the 60 years since. On screen, vibranium was also used to create a few gadgets in Agents of SHIELD, and was used by Ultron to make his newer fancy body in Age of Ultron — a subplot that also served to introduce black market vibranium seller Ulysses Klaue. Needless to say, vibranium is pretty in-demand in the MCU.
So, what does a precious metal have to do with Civil War? Well, vibranium is only found in the African country of Wakanda, which Black Panther (aka T'Challa) rules. In the comics, Wakanda is an incredibly technologically advanced country that has managed to mostly keep its technology contained in one place through isolationist policies. Black Panther's connection to vibranium has a few consequences in Civil War. For one, it means that Black Panther has a suit made with vibranium (which is extremely malleable), complete with claws, so he's pretty indestructible. But, it also means that Black Panther has some real motives to join the Civil War.
Ultron's use of vibranium leads directly to Black Panther's introduction to the MCU, as Marvel Studio's Kevin Feige described in a recent interview with Birth.Movies.Death. "I think he and his father are saying, 'A bunch of vibranium just got out of here and wreaked a lot of havoc. Maybe we can't stay behind these borders anymore," Feige said.
Furthermore, it's likely that Howard Stark came across the vibranium for Cap's shield in a completely shady way. I would imagine that vibranium being Captain America's weapon of choice is, essentially, a huge slap in the face to Black Panther, not to mention a very obvious symbol of colonialism. I, for one, wouldn't be surprised to see the conflicts surrounding vibranium expanded upon in the upcoming Black Panther movie, which will actually take place in Wakanda.