The United States established early control of space after the discovery of the tunnel drive. For decades, it secretively used this advantage to explore deep space leading up to the colonization of the planet New Washington. During this period, the US Space Command gained prominence by asserting it self as the dominate department within the U.S. military, allowing for the building of a fledgling space force to protect its newly discovered claims from other governments.
The evolution of the American warship from the small gunships of the a century ago, has evolved into some of the largest vessels now plying Terran space. The Mars-class carrier for example, is a marvel of American ingenuity followed by the Bolivia-class assault ship. In terms of sheer size from the Terran core, only the Chinese Star Force, has demonstrated the ability to field large warships.
The Chinese Star Force was designed to compete against the American Space Force. Although both governments have not competed directly in terms of interstellar expansion, the Chinese government asserted itself as a direct counter to the U.S. military machine. Similar to their counterparts, the Star Force has field two of the largest warships operated throughout the Terran Core.