The Stalwart IS (Impasse Security) system integrates the design elements of a high security fence with an anti-ram barrier. The Impasse framework provides a platform to incorporate various security peripherals required on high security perimeter designs. Intimidating design elements of the Impasse palisade security fence provide the best deterrent to intruders. The components that define the Impasse fence framework are used to carry the anti-ram cable transforming the Impasse fence into the Stalwart IS crash fence system. The Stalwart anti-crash barrier has been engineered and tested in compliance with current ASTM F2656-07 (Standard Test Method for Vehicle Crash Testing of Perimeter Barriers), and meets the demand for multiple vehicle threats.