This paper presents a theoretical treatment of the nonlinear propagation of strong electromagnetic waves through weakly ionized water vapor. It shows that when the parameters of propagation are held within certain constraints, analytical solutions may be obtained which describe the amplitude of such waves. These solutions are applied to the question of propagation through rocket exhaust gases. A novel method is described for altering the attenuation experienced by a signal sent from the ground, through the exhaust gases, to the missile. This is accomplished by broadcasting a powerful 'sacrificial' wave from the missile to alter the electrical characteristics of the exhaust. (Author).