Marvel Comics fans are well aware that Iron Man and Captain America have expressed their fair share of differences throughout their respective superhero careers, though one comic does a better job than any other at explicitly stating the true moral difference between the two Avengers.
Iron Man and Captain America first crossed paths in Avengers #4 by Stan Lee and Jack Kirby after the Avengers recruited Cap for the team following their discovery of his body frozen in ice (technically Namor’s discovery, but the Avengers weren’t aware of that). While their time working together was initially pretty short-lived–as the original Avengers line-up left the team in issue #16–it was clear that they had nothing but admiration for each other. Iron Man saw Captain America as the greatest soldier who ever existed, and Cap held Iron Man in the highest regard as a hero. As time went on, however, the two started to become less fond of each other, with their ultimate fallout coming in the form of the first Civil War event–and now fans know exactly why that is.
In Iron Man #24 by Christopher Cantwell and Angel Unzueta, Iron Man and War Machine are going after the villainous Cobalt Man as the villain recently took ownership of the Mandarin's Ten Rings. After Tony and Rhodey faced off against Cobalt Man for the final time, it was revealed that the villain wasn’t a villain at all–Cobalt Man was Riri Williams aka Ironheart in disguise. Williams learned of the Ten Rings being sold on the black market and came up with a plan to retrieve them herself. When Riri revealed herself to Tony and Rhodes, Tony immediately requested that she give him the Ten Rings to handle them appropriately. However, Riri argued that she should hold on to them to conduct her own research and ensure that they stay out of the wrong hands herself. After much arguing, Tony finally decides to trust Riri with this task, saying it “felt like the most right thing”.
Iron Man’s Morals are Much Less ‘Black & White’ than Captain America’s
While Iron Man’s justification for why he let Riri Williams take off with the Mandarin’s Ten Rings without putting up more of a fight had nothing to do with Captain America, it was incredibly insightful into how Tony looks at every situation. Iron Man doesn’t perceive ‘right and wrong’ as literal descriptors of any given situation, but rather reads the situation itself and comes up with the ‘most right thing’ in that specific instance. Captain America, on the other hand, has made it clear that there is no room for compromise when considering what is right and wrong. In fact, in Amazing Spider-Man #537 (during the Civil War arc), Captain America gave an entire speech where he talks about standing firm on what is absolutely right, no matter who disagrees or how impossible the odds.
Essentially, if Captain America was in Iron Man’s shoes when speaking with Ironheart about what to do with the Ten Rings, it is likely Cap would see the Ten Rings as the source of evil and destruction that the Mandarin used them for in the past, and wouldn’t allow Riri to have unsupervised control over them. Tony, however, knew that forcing Riri to turn over the Ten Rings–even if that had been the ‘right’ thing to do–would create conflict where there needn’t be any, so he did the ‘most right thing’ in this specific situation by deciding to trust Ironheart with the Rings–a perfect example of how Iron Man’s morals differ from Captain America’s.