Combined arms operations have usually resulted in the quickest least costly victories because they cause the enemy several dilemmas at once, which tends to overwhelm them. For example strategic bombing is rarely deceisive. At best it is a set up for future attacks. However tactical air attacks combined with ground forces that include armor and infantry "fix" the enemy and are usually devastating. Psyops I think fall into the setup category, although there were some examples during the major combat operations phase of Operation Iraqi Freedom where psyops caused the enemy to make irrational attacks on tanks and other weapons systems that destroyed them.