Warning: spoilers for Avengers #47!
In Marvel's Civil War, Captain America and Iron Man nearly killed each other over their difference of opinion on the Superhero Registration Act. However, in the latest issue of the Avengers, Steve Rogers and Tony Stark are surprisingly comfortable joking about starting a war in the Marvel Universe - proving a lot has changed since the heroes first went at it.
In Marvel Comics' Civil War, the United States government enacted a new law called the Superhero Registration Act, where heroes were forced to register with the government and follow its rules. Captain America greatly opposed the act while Iron Man supported the law. The differing viewpoints led to a civil war between Marvel's greatest heroes, as Iron Man and Captain America went from friends to enemies. Steve Rogers almost killed Tony Stark before the event came to a close. Marvel would follow the event up with the critically maligned Civil War II, featuring Iron Man and Captain Marvel butting heads over using a new Inhuman to arrest people for future crimes. The original Civil War was adapted on the big screen in the Marvel Cinematic Universe in Captain America: Civil War.
In Avengers #47 by Jason Aaron, Javier Garron, David Curiel, and Cory Petit, Iron Man and Captain America lead a rescue mission to save She-Hulk from the Winter Guard. The Russian superteam subdued the hero after infiltrating Avengers' Mountain in hopes of making her pay for decimating part of Moscow. In their stealth armor, Captain America and Iron Man take down the Winter Guard's outside forces. After making their way to the entrance, Steve tells Tony they can't stick around long enough to start a war. Iron Man's response? "Ah, but you and I are always so good at that."
Tony is always up for a good zinger in tough situations and enough time has likely passed where they can joke about Marvel's Civil War. But still, it feels a bit to soon to crack wise about an event which left multiple people dead. But, considering death is anything but permanent in comics, Stark's jokes are probably fine.
Who knew that more than 15 years after Iron Man and Captain America initially battled it out over the events of Civil War, that there would be a time where they could joke about the incident. Captain America and Iron Man know a thing or two about inadvertently starting a war, so jokes in a time of crisis are more than appropriate. Avengers #47 is in comic book stores now.