30 years ago - Scott Sawyer is born.
12 years ago - 18-year-old Scott joins the air force.
7 years ago - 23-year-old Scott is selected to join General Wade Elling's Metasoldier program. His body is taken out of phase so that he can power the warmaker weapon systems.
4 years ago - 26-year-old Scott takes over America's seat in the Global Guardians as Warmaker-One. When the strain of supporting the Warmaker weapons prove too much, he kills Dorah Leigh for rejecting him. He battles Rocket Red & August General In Iron, and is finally killed by Skyrocket.
If you're going to do the Global Guardians, you need to at least look at the International Ultramarine Corps. They were one of the one-off teams built by Grant Morrison for his JLA run, specifically built to show General Elling's efforts to make a government superhero team. Most of them were the sort of surreal half-science that often permeates Morrison's more personal work, and even Warmaker's concept of being 'out of phase' was pretty conceptual. In the end, the Ultramarines built a standalone team that featured several members of the Global Guardians, making them a sort of replacement team.
Our Guardians are obviously more closely associated with the original team, but the idea of incorporating a character from the Ultramarines is actually a clever one. The story we used for him actually borrowed heavily from the Superman Animated Series character Sgt. Corey Mills, who wore a suit of neurally interfaced armor built by Henry Irons for Lexcorp, but who eventually was driven mad by his own armor. We've used a similar story design to stage a crisis within the ranks of the Global Guardians.
Truth be told, making the offending character in their crisis an American was a deliberate choice. If the team is going to reflect the actual world at all, then you have to address the obvious distrust the rest of the team will have for the American character. By putting a face to that distrust, we can actually bring the team together against that threat.