Captain America's greatest worry about the Avengers signing the Sokovia Accords in Captain America: Civil War actually came to pass years earlier in the 1993 comics crossover Avengers/X-Men: Bloodties. While the Avengers operated under U.N. supervision in the comics at the time, they were forbidden from interfering in a civil war in the nation of Genosha. In true Avengers fashion, however, they do not let bureaucratic oversight stop them from doing what they think is right.
The 2016 blockbuster film Captain America: Civil War sees the Avengers divided about signing the Sokovia Accords, which would place the team under the authorization of the United Nations. While a faction of Earth's Mightiest Heroes agree with Iron Man that the Avengers need to be put in check, Steve Rogers disagrees. He doesn't like the idea of handing over authority to a panel of bureaucrats, fearing that they could come into conflict about where to send the Avengers. "What if this panel sends us somewhere we don't think we should go?" he asks. "What if there's somewhere we need to go and they don't let us?"
That exact scenario comes to pass in Bloodties, a five-part crossover that spans across both X-Men and Avengers titles. The story sees a civil war break out between humans and mutants in Genosha. The war is incited by Fabian Cortez, a mutant follower of Magneto who has kidnapped the daughter of Avengers Crystal and Quicksilver (who at the time was still believed to be the son of Magneto). At the time, the Avengers team charter — which every member has signed without conflict — dictates that the U.N. has authority over the team. S.H.I.E.L.D. Director Nick Fury informs the Avengers that the U.N. has decided the Genosha situation will remain a strictly domestic affair and they are not to interfere, which does not sit well with the heroes. When they decide to help Crystal rescue her daughter, Fury dispatches S.H.I.E.L.D. forces to keep the Avengers contained in Avengers Mansion.
A fight breaks out between the Avengers and S.H.I.E.L.D. and Captain America is able to lead a contingent of Avengers that includes Scarlet Witch, Crystal and War Machine on a mission to Genosha. Meanwhile, Hawkeye leads a group directly into the U.N. headquarters where they confront the General Assembly. After some debate, Black Widow announces, "From this day forward, people, the Avengers are out of politics and back in the business of avenging." In stark contrast to the MCU, the decision to join — and later leave — the U.N. does not cause internal strife within the ranks of the Avengers. The team is fairly unanimous that aligning themselves with world governments is the best way to facilitate their goals of keeping Earth safe. Similarly, the Avengers are largely on the same page about leaving the U.N. and returning to self-governance. And to underline the idea that the U.N. can't really keep these superpowered beings in line, once the Avengers decide to strike out on their own, nothing can be done to stop them.
Despite being a major source of conflict, the Sokovia Accords are pretty quickly abandoned in the MCU. When faced with the threat of Thanos in Avengers: Infinity War, all the heroes who refused to sign are welcomed back into the fold. And while the U.N. charter provides some dramatic tension in Avengers/X-Men: Bloodties, Earth's Mightiest Heroes similarly face little consequence for abandoning it when it becomes inconvenient. This showdown between the Avengers and the U.N. shows that Steve's fears about the Sokovia Accords in Captain America: Civil War were spot-on, and that he was right when he said, "We may not be perfect but the safest hands are still our own."