Iron Man’s arc reactor has seen many different versions over the years.
It is also after all the proof that Tony Start has a heart.
But contrary to what one might think, the original idea for the reactor was not hatched out of Stark Jr. but Stark Sr.
Howard Stark had intended to build the arc reactor as a means to end the Cold War.
He built the first prototype to power the Stark Industries headquarters in Los Angeles.
But upon further inspection, he deemed the technology unfinished.
It took the genius of Anthony “Tony” Stark, Iron Man himself, to complete his father’s vision, although at that time he might not have known this little fact.
Somehow, Howard had figured out that an undiscovered metal might be the answer to finally creating a sustainable arc reactor, without poisoning the host body.
Tony Stark, one of the greatest geniuses in the MCU, had made his first arc reactor while being half dead with a box full of scraps.
So when he got proper resources and time, it was in no time that he figured out how to power his Iron Man suit with the arc reactor, and without dying of chemical poisoning.
Howard had left behind clues for his son to figure out how to make it work, and build an arc reactor that could be deemed safe as well as sustainable.
And although Tony’s use of the arc reactor was vastly different from what his father had envisioned, he had actually managed to make the idea into a reality.
Howard Stark had attempted to build the arc reactor to end the Cold War, as we see in Iron Man: Public Identity.
He was opposed to nuclear technology taking over and wanted to have an alternative power source.
Something that could be both renewable and sustainable.
The destructive power of nuclear energy was at the forefront during the Cold War, and Howard feared that nuclear weapons could be the end of everything.
Thus, he started working on the idea of the arc reactor. He also did not want to help one singular nation with its powers, but the whole world.
Howard enlisted scientists from all over the world for something he called “The Unity Project”.
He studied the Tesseract and wished to harness its energy with the idea of providing a limitless power source that could provide clean, renewable energy for the future of mankind.
But unable to find any way Howard, along with a Russian scientist Anton Vanko, managed to create the first arc reactor – a large scale technology devised to provide sustainable power.
In Iron Man II, we see Nick Fury as he provides Tony with all the research Howard had done on the arc reactor, to help Tony cure himself.
Fury told him about what happened between Anton and Howard, and why Howard had him deported back to Russia.
“Anton saw it as a way to get rich and when your father found out, he had him deported. When the Russians found out he couldn’t deliver, they shipped his ass off to Siberia. He spent the next twenty years in a vodka-fueled rage.”
This was why Ivan Vanko later came to America to take revenge on Tony for what his father did to Anton.
Howard had taken full credit for building the arc reactor, not mentioning Vanko’s contribution, who we later find was also involved in espionage.
After Vanko’s deportation, The Unity Project was scrubbed.
The United States government did not want the technology falling into the wrong hands, like when Vanko had tried to sell the blueprints of the arc reactor to the highest bidder for money.
Howard became focused within SHIELD, the newly formed secret intelligence agency.
And the potential of the arc reactor faded until Tony took up the work himself. Instead of continuing his father’s project, Tony built a miniature version of the arc reactor that was used to power his Iron Man suit.
And although it did not power nations or the world at large, the arc reactor was used by Tony to defeat many threats the world faced, against terrorists or even aliens, like in The Avengers.