The deployment of chemical warfare agents (CWAs) has presented the need to develop smart, functional materials that are able to not only detect the presence of CWAs but also actively protect military personnel. Although current technologies prevent exposure to nerve agents, the limited breathability of the materials severely hinders the duration of their active use. Functional materials that offer breathable states in safe environments while protecting soldiers in the presence of active agents are thus highly desired. We report herein the synthesis and utility of CWA-responsive polymers that simultaneously undergo a color change and gel collapse upon exposure to CWA mimics. By covalently tethering these polymers to vertically-aligned carbon nanotube membranes, we demonstrate a dynamic material with a rapid, selective, and reversible transition from a swollen, highly breathable state to a collapsed, protective state.