This paper considers the study of cooperative transportation of a cable-suspended load with two aerial robots and without explicit communication. The role of the internal force for the asymptotic stability of the beam-position/beam-attitude equilibria is analyzed in depth and explained thoroughly. Using a nonlinear Lyapunov-based approach, we prove that that if a non-zero internal force is chosen then asymptotic stabilization of any desired beam-position/beam-attitude configuration can be achieved by using a decentralized and communication-less master-slave admittance controller. If, conversely , a zero internal force is chosen, as done in the majority of the state-of-the-art algorithms, the attitude of the beam is not controllable without communication. Non-zero internal force can be interpreted then as a fundamental factor that enables the use of cables as implicit communication means between the two aerial vehicles in replacement of the explicit ones. The theoretical findings are validated through numerical simulations with added noise and realistic uncertainty.