James Rhodes was a pilot in the United States Marines stationed in South Vietnam during the U.S. military involvement in Southeast Asia. Blasted out of the sky by enemy rockets, Rhodes managed to land in one piece and was attempting to get his craft airworthy when inventory Tony Stark, clad in his Iron Man armor, happened to be passing by. Stark had just completed his original armor, had avenged his fellow prisoner Professor Yinsen, and was trying to make his way through the jungle to the American defense perimeter. Attacked by the Viet Cong, Iron Man proved to Rhodes they were on the same side, and Rhodes allowed him to drain the helicopter's batteries to recharge his armor. The two then trekked through the jungle together, finely discovering a hidden enemy rocket base. Stealing an enemy helicopter, they destroyed the base, and flew to the nearest American encampment. Before leaving Vietnam for the United States, Stark offered Rhodes a job as a pilot as soon as his military stint was over. After a succession of other jobs, Rhodes finally accepted Stark's offer and became his personal pilot and chief aviation engineer. While working at Stark International, Rhodes aided Iron Man in his battles against such foes as the Roxxon Oil Company, Justin Hammer, the Dreadnoughts, and Obadiah Stane.
When devastating personal problems caused Tony Stark to abuse alcohol and become incapable of using the Iron Man armor responsibly, Rhodes put it on in order to defend Stark International from the criminal Magma. He offered to return it but Stark insisted Rhodes take on the responsibility of being Iron Man for a while to enable Stark to enjoy himself. Reluctantly Rhodes agreed, and after Stark employee Morley Erwin helped him figure out how to operate the armor, found himself in battle with such foes as Thunderball, Firebrand, Krang, Flying Tiger, the Radioactive Man, the Mandarin, the Zodiac, and Vibro. Although he was unable to help Stark from being swindled out of proprietorship of Stark International by Obadiah Stane, he did prevent Stane from taking custody of all of Stark's Iron Man armors. With Morley Erwin and his sister Clytemnestra, Rhodes embarked upon a brief career as a mercenary in order to obtain funds with which they could begin a new business venture. By the time they succeeded in raising sufficient capital, Tony Stark had recovered from his several months-long alcohol binge, and offered to join them. The four moved out to Silicon Valley, California, where they founded Circuits Maximus, a small electronics design firm. Stark still was not interested in resuming his Iron Man role and gave his blessing to Rhodes to continue. Rhodes was initiated into the established ranks of superhuman champions when he became one of those who participated in the first Secret Wars. Soon afterwards, he was invited to join the newly-founded West Coast Avengers by chairman Hawkeye, who believed him to be the original Iron Man. After proving his worth to the group, Rhodes revealed to them he was Iron Man's replacement.
Soon after first donning the armor, Rhodes began to get severe headaches because the cybernetics in the helmet had never been properly recalibrated for his brain patterns. Working in close proximity with Stark again, Rhodes began to fantasize that Stark secretly disapproved of him keeping the armor and wanted it back. This led to increasingly hostile and irrational behavior on Rhodes' part. As work therapy, Stark began to construct a new set of armor based on his original armor's design. When Rhodes finally began to endanger the lives of innocents by his behavior, Stark donned the unsophisticated new armor and managed to stop Rhodes' rampage. Ashamed of his behavior, Rhodes went off to look for a cure for his headaches when adjusting the helmet to his brain patterns did not end them. Stark went to the West Coast Avengers to tender Rhodes' resignation, and was invited by Hawkeye to use the laboratory facilities to create a new state-of-the-art set of armor. Rhodes returned to Circuits Maximus after the Indian mystic Shaman helped him cure his headaches, and briefly joined forces with Stark battling Obadiah Stane's latest machinations against them. Rhodes was injured in an explosion Stane engineered that destroyed Circuits Maximus and killed Morley Erwin. Consequently, he could not assist Stark in his final assault on Stane, an assault that ended in Stane's death.
Rhodes joined Stark in his new business venture, but even after his bones mended, he was reluctant to put the Iron Man armor on again. Stark had resumed his responsibilities as Iron Man using the new state-of the-art armor, and Rhodes not only felt a second armored Avenger would be superfluous, he also felt contrite about his irrational period.
Several years later, Tony Stark "died," and Rhodes was named CEO of Stark Enterprises. It was at this time that Stark Enterprises created the War Machine armor and Rhodes briefly took the place of Iron Man (even replacing him in the Avengers West Coast). However, when he discovered that Stark was not dead, Rhodes became furious and resigned, severing his friendship with Stark. The two would occasionally team up to battle the evil that was trying to take over, but the friendship of old was no longer the same. Around this time Jim became romantically involved with Rae LaCoste.
War Machine went on his own for some time. Jim traveled to the small African nation of Imaya in an attempt to free peace activist Vincent Cetewayo. Cable and Deathlok (Michael Collins) also traveled to the war-torn country, and Nick Fury quickly sent a SHIELD team to hope the situation would stabilize. In the resulting revolution the country's dictator was overthrown, but Cetewayo had been murdered by a mysterious Advisor, who warned Jim that he is present in every conflict. Jim continued to adventure and worked for Cetewayo's company Worldwatch, which investigates human rights abuses. One of the SHIELD agents present, Sheva Joseph, left to work with Rhodes. Jim continued to adventure, but could not find someone capable of repairing the armor. Returning to Stark, the two had a confrontation about each other's recent actions. This was interrupted by the Mandarin. After Mandarin was defeated, the armor was fixed.
While visiting family and friends in Philly, Rhodey stumbled onto a group of armor wearers who hunt for sport. Tracking the leader Locomotive Breath to Slorenia, he discovered that atrocities were occurring and alerted both Worldwatch and Force Works.
Soon after that, he was contacted by Sheva, who was investigating some neo-Nazi activity. Rhodey and Nick Fury answered her call to find a rabid faction that was attempting to send modern weapons to WWII era Germany. Rhodey followed, meeting a younger Fury, the Howling Commandos as well as Cap and Bucky Barnes. The "Zeitkrieg" was halted, although the War Machine armor was lost when time shifted.
On vacation, Jim suddenly acquired a new alien costume, the Eidolon Warwear. A mysterious woman named Skye said only that he would need it. Hearing that something terrible had happened, Rhodes returned to the Avengers. Rhodes joined the Black Widow, the US_Agent and Hawkeye to find a way to stop Tony Stark. A confrontation changed little, and Rhodey helped Force Works to disable some weapons.
He went into space to disable the STARCORE satellite. There he found another Eidolon wearer named Dirge, apparently having been sent by Kang. A dying Skye explained a bit more about the Eidolon's history, and the other wearer was destroyed. Eventually, Stark broke Kang's control and sacrificed his life to save his friends. After his death, Rhodes returned to Stark Enterprises, which was soon bought out by Fujikawa; his attitude about Stark changed for the better as well.
Sheva Joseph began to rapidly age and soon died, a side effect from their earlier time travel. Jim's Eidolon was discovered while he was being examined for the same condition, and he briefly got into a quarrel with SHIELD who wanted to quarantine him and study the armor.
As War Machine, Jim Rhodes discovered that Fujikawa was trying to gain access to some of Tony Stark's old technology. In order to save that technology from falling into another's hands and to preserve the legacy of his old friend, he purged the computers of Fujikawa in order to destroy all the information about Stark's armor technology. In doing so, he sacrificed his alien costume by downloading it into the computers and sending it on a "search and destroy" mission.
No longer wishing for any superhero identity, Rhodes returned to civilian life to start up his own salvage company. Upon Stark and the other heroes' return from Counter-Earth, the two renewed their friendship, also dealing with the new War Machine, Parnell Jacobs.
Rhodes had heavily invested in Grace & Tumbalt due to their stated purpose of improving urban ethnic neighborhoods. While investigating the death of his sister Jeanette, he learned the company was corrupt, using their resources to fuel gangs and drugs. This led to his membership in The Crew.
James was hired by ONE and serves as a Direct Command Officer and combat instructor for Sentinel Squad ONE.
Post-Civil War, Rhodey is participating in the Intiative recruitment and training program.