 One of the primary advantages in having military reserves is that they increase the available manpower by many fold in a short period of time, unlike the months it would take to train new recruits or conscripts, since reservists are already trained.Reservists are often experienced combat veterans which can increase not only the quantity, but the overall quality of the forces.Having a large reservist pool can allow a government to avoid the costs, both political and financial, of requiring new recruits or conscripts.