undercover operation

work undercover

undercover agent

undercover apparatus

undercover intelligence asset

undercover international apparatus

undercover movement

undercover work

clandestine operation; covert operation

humanitarian operation; humanitarian relief operation (HUMRO)

PZ operation (pick-up zone operation)

noncombatant evacuation operation (NEO); non-combat evacuation operation

aeromobile operation

African Union / United Nations Hybrid operation in Darfur (UNAMID)

air defense operation

air logistic support operation

air operation

airborne and amphibious operation

airborne assault operation

airborne/ amphibious operation

air-land operation

air-landed operation

airmobile operation

alien migration interdiction operation

Alliance operation

allied joint operation

amphibious operation

anti-air operation

anti-terrorist operation

area denial operation

area interdiction operation

army operation

Article 5 operation