first line defense
- immunityProtected from harm
- barrierObstruction preventing passage
- skinBody's outer layer
- shieldHandheld defensive armor
- frontlineCombat's forward position
guard · patrol · sentinel · white blood cells · mucus · perimeter · antibodies · resistance · protection · fortification · troops · rampart · watchmen · outpost · firewall · checkpoint · vanguard · soldiers
defensive sequence/priority
first line defenselast resort
Final available option
fallback position · rear guard · reserve forces · defense in depth
offense vs defense
first line defensefirst strike
Initiating combat unprovoked
preemptive strike · aggression · offensive · assault · offensive line
vulnerability vs protection
first line defensevulnerability
Openness to harm
defenselessness · undefended · weak point · breach · unprotected