Descendants of Terra. A History of the Early Interstellar Era by Professor W.S. Templehill
The combined military government formed in 2017, six months after the Cataclysm, took over most of the responsibilities of the various civilian governments of the US and Europe and streamlined the remaining civilian organizations. As the USA was by far the most powerful nation to survive the Cataclysm, most of the upper echelon officers within the new government were American and government policy was formed on a US-centric basis. Some other countries, notably France, objected to measures such as English being the official language of the new United Terran States and the dollar being the only acceptable currency. However, such complaints received little sympathy from countries more interested in survival than linguistical differences and extremely grateful for the mainly US technology that held back the bulk of the comets and meteors. The European nations did succeed in convincing the new government to adopt the metric system of measurements rather than the imperial system used by the US and large sections of the UK population. Despite many trials and tribulations, by 2035, the United Terran States was one nation in reality as well as administratively.
As time passed, the military permeated every aspect of society with military personnel performing many of the tasks that were carried out by civilian organizations before the Cataclysm. Although repressive measures were introduced in the immediate aftermath of the disaster, they were slowly lifted as the years passed and Humanity