Plans for NextGen include the implementation of Net-Centric Operations (NCO) as the underlying mechanism to more effectively manage National Air Transportation System (NAS) resources. NCO mechanisms will provide the means for all agents operating in the NAS to self-synchronize in the presence of changing situations and probabilistic forecasts. Applications of NCO in other domains (e.g. military war fighting and health care) have identified the importance of developing rules and procedures for NCO to ensure that the behavior of all agents yields a net benefit to the system. This paper describes the results of a multi-agent simulation of the evolution of Airline Operation Center (AOC) decision-making for trans-continental route selection when demand for the routes is in excess of the available slots. The results show the emergence of hawk and dove alliances in AOC strategies. In some cases, these strategies yield improved performance and utilization of NAS resources. The implications of these results are discussed.