There are concerns that the rate at which China and Russia can field new technologies exceeds the rate at which the U.S. Air Force (USAF) can replicate those technologies in operational test and training infrastructure (OTTI). The authors of this report estimate the rate at which China and Russia field new threats and examine the costs and benefits of keeping USAF OTTI at pace with new adversary capabilities. The authors find that China and Russia are fielding new threats at rates exceeding that at which the USAF has historically been able to field new OTTI and that significant investment is required to keep OTTI at pace with adversary technology developments. This analysis provides a target for funding and fielding timelines that, if achieved, could edge the USAF training community closer to keeping the training environment at pace with new adversary technology.