According to the Air Force, it had to develop a strategy that can accelerate domestic companies' quest to get National Security Space launch requirements. That's due to the government's mandate to move away from reliance on foreign rockets and the retirement of ULA's Delta IV. Aside from Blue Origin, the two other companies that won a contract with the Air Force are United Launch Alliance (for its Vulcan-Centaur booster) and Northrop Grumman (for its OmegA launch system).
Lt. Gen. John Thompson, the Air Force's Program Executive Officer for Space and the project's commander, said in a statement:
"These awards are central to the Air Force goal of two domestic, commercially viable launch providers that meet National Security Space requirements. These innovative public-private partnerships with industry provide a path to develop launch vehicles to assure access to space, address the urgent need to transition away from strategic foreign reliance, and provide responsive launch capabilities to the warfighter."
Blue Origin has announced on Twitter that it will pursue a launch site at the Vandenberg Air Force Base, so the New Glenn can blast off either from the California base or from Cape Canaveral in Florida. According to Parabolic Arc, the company expects to complete its work on New Glenn by July 21st, 2024, after which the rocket will start flying national security missions.