Warning: contains spoilers for X-Men: Hellfire Gala #1!
The X-Men's Krakoa era is coming to an end, and only Iron Man knows exactly how and why. Tony Stark knows exactly what happens when experimental technology gets out of control or is used by the irresponsible and/or nefarious, and has firsthand knowledge of these experiences. Now in X-Men: Hellfire Gala #1, Iron Man knows exactly what will destroy the X-Men's paradise island: the ability to resurrect mutants from the dead.
As of the new Dawn of X X-Men reboot by writer Jonathan Hickman, the mutants of Earth have the ability to bring their own back from the grave. While the X-Men have always had a rather infamous tendency to never stay dead for long, this technology made it official, and now no mutant could ever die (so long as the technology was maintained). The mutants kept their resurrection protocols a secret, but the X-Men leader Cyclops eventually leaked the story to the press...and now all of humanity know the mutant population can cheat death.
In X-Men: Hellfire Gala #1, written by Gerry Duggan with art by Kris Anka, Russell Dauterman, Matteo Lolli & CF villa, Tony Stark has a poignant conversation with his former lover, Emma Frost. "You have an incredible technology," he says, referring to the resurrection protocols of Krakoa. "Something that will change the world, something worth killing over...the technology will proliferate, or it will be destroyed, along with who knows what else?" Iron Man speaks from experience, as his armor technology was widely coveted by the many supervillains of Earth, especially during the events of Armor Wars.
Tony Stark's technology was eventually stolen during Armor Wars, leading to the rise of multiple supervillains wearing and/or using Stark technology. Stark's many struggles with his technology eventually led to self-destructive behavior and a near-death experience. The X-Men's situation is arguably worse; not everyone would find use for an Iron Man suit, but everyone on the planet - human and otherwise - wants to cheat death, and even the might of the entire mutant population of Krakoa would not be able to fend off the armies of multiple countries (should the conflict escalate in the future).
The X-Men were right to keep their resurrection protocols a secret, but such a massive, game-changing technology couldn't possibly be kept from governments for long. The resurrection protocols only work for mutants - but humans don't know this, and most likely wouldn't even care if they did; the X-Men now have a technology that sets them apart from humans. Iron Man surmises that such a technology will eventually be the X-Men's undoing; even if humans understood they could never use it, they would ensure the mutants wouldn't be able to either.
X-Men: Hellfire Gala #1 is available now from Marvel Comics.