Operation: WARLORD

With the Earth being cleared of opposition, and the Martian Campaign coming to a close, the United Nations Space Command launched Operation: WARLORD, a massive buildup of ships and weapons paired with a determined recruitment drive. The latter was determined to recover any losses sustained over the last four years and then some, aiming to recruit around ten million soldiers and sailors. Initially believed to be a foolishly optimistic and utterly out-of-reach number, the recruitment offices found an awe-inspiring reversal - in seven days, approximately fifty million men and women volunteered for service in the armed forces of the United Nations Space Command Defense Force. 
As for shipbuilding, the UNSCDF Navy still had all inner system UNDF shipyards and raw materials to work with. However, with the unification of national assets, the UNSC suddenly found itself in possession of dozens of facilities and thousands of personnel, increasing shipbuilding capacity threefold. Additionally, the UNSC was the sole beneficiary of all the technological advancements made by first the UNDF, and also by every major national shipbuilder for the last twenty years.