A loyal and competent commander.
He was involved in the early battles of the conflict in Estonia. He stays in contact with the GDI commander after contact is lost with GDI Command and General Mark Jamison Sheppard as funding for GDI is cut by the UN as part of their investigation into the Białystok scandal.
Based on his appearance in the final scene he appears in, he has contracted Tiberium poisoning in the line of duty. In this briefing, he mentions he will be arriving with the river convoy to take out the Nod base. In the mission that follows, all gunboats are destroyed by Nod's new fearsome weapon, the Obelisk of Light, which, according to the mission's text briefing, GDI had heard rumours about about but had no details on. Given the fact this is Carter's final appearance, it is assumed that he dies in that failed assault.