A ballistic armor system adapted to protect against penetration of the armor system by projectiles, including a first armor layer; a second armor layer, in which the second armor layer is mounted in spaced-apart relationship to the first armor layer, the relationship defining a void volume between the first armor layer and the second armor layer; and a fluid disposed in the void volume, in which the fluid includes a viscoelastic surfactant at a concentration sufficient to exhibit pseudosolid elastic behavior. The fluid may be removed from the void volume by use of a suitable breaker.