agriculture
area
barb
barbed
barrier
blue
bob
bobbed
border
boundary
camp
capture
captured
concentration
danger
district
entry
fence
frontier
ghetto
iron
metallic
military
mine
minority
prison
prisoner
protection
rebellion
refugee
rural
security
sharp
sign
sky
steel
stop
submission
surrender
symbol
territory
torture
trench
vertical
victim
war
warfare
warn
wire