U-joint (universal joint / universal coupling)
U – UNIFORM
UAS Control Segment (UCS)
UAV company
UAV imagery
UHF communications equipment
UHF radio receiver transmitter (RRT)
Ukraine Defence Contact Group (UCG)
Ukrainian Armed Forces
Ukrainian Cyber Alliance
Ukrainian hacktivist groups
ultimate destination (final destination)
ultimate disposal
ultimate user
ultimatum
ultrahigh frequency (UHF)
ultrasound
ultraviolet radiation
ultraviolet (UV)
umbilical (cable, hose)
umbrella agreement
umbrella approach
umbrella barrage
umbrella fighter
umpire
umpire control organization
UN-led International Police Task Force
UN-mandated force
unacceptable damage
unarmed
unarmed combat
unattached
unauthorized activities
unauthorized disclosure of classified information
unbiased approach
unblocking
unbroken flow of supplies
unbuttoned driving
uncertain environment
uncertainty
unclassified (security classification)
unconcealed position
unconditional discharge
unconditional surrender
uncontaminated area
uncontrolled airspace
uncontrolled crossing point
uncontrolled mosaic
unconventional warfare (UW)
unconventional weapons
uncorroborated
Uncrewed Air(craft) / Aerial System (UAS)
uncrewed surface vessel
under armor auxiliary power unit (UAAPU)
under arms
under barrel grenade launcher (UBGL)
under canvas
under command of
under cover of
under fire
under hatches
Under Secretary of Defense for Acquisition, Technology, and Logistics (USD AT&L)
Under Secretary of Defense for Intelligence USD(I)
Under Secretary of Defense (USD)
under-strength unit
under-vehicle improvised explosive device (UVIED)
undercarriage
undercover operation
undergrowth
underpass
underslung load
underwater-launched missile system
underwater sticky foam
underwater target
underwater-to-air missile
underwater-to-surface missile
underwater-to-underwater missile
underway replenishment
underway replenishment group
underway support (naut.)
undesired effects
undocking
UNDP Bureau for Crisis Prevention and Recovery (BCPR)
UNDP Small Arms Demobilization Unit (SADU)
UNDP Thematic Trust Fund for Crisis Prevention and Recovery
unencumbered balance
uneven ground
unexploded ordnance disposal (UOD)
unexploded ordnance (UXO)
unfavorable terrain
Unfix BAYONETS!
unfordable stream
unforeseen circumstances
unfriendly act
unidentified flying object (UFO)
unified
unified action
Unified Combatant Command (UCC)
Unified Command Plan (UCP)
Unified Tactical Control System (UTCS)
unified video dissemination service (UVDS)
uniform
Uniform Code of Military Justice (UCMJ)
unilateral operation
unimpeded access
unimproved road
uninhabited
unintended effects
unintentional radiation intelligence (RINT)
uninterrupted supply
unique identifier
uniservice
uniservice command
uniservice force
uniservice training
unit
unit aid post (UAP)
unit assigned
unit basic load (UBL)
unit cohesion
unit commitment status
unit designation
unit distribution
unit insignia
unit of employment
unit of equipment
unit of fire
unit of measure
unit of supply
unit ready to move and fight
unit size
unit staff
unit tables of organization and equipment
unit training
unit trains
unitary enterprise
United Nations Advance Mission in Cambodia (UNAMIC)
United Nations Advance Mission in the Sudan (UNAMIS)
United Nations Angola Verification Mission (UNAVEM)
United Nations Aouzou Strip Observer Group (UNASOG)
United Nations Assistance Mission for Iraq (UNAMI)
United Nations Assistance Mission for Rwanda (UNAMIR)
United Nations Assistance Mission in Afghanistan (UNAMA)
United Nations Assistance Mission in Somalia (UNSOM)
United Nations Charter
United Nations Civilian Police
United Nations Civilian Police Mission in Haiti (MIPONUH)
United Nations Civilian Police Support Group (UNPSG)
United Nations Confidence Restoration Operation in Croatia (UNCRO)
United Nations Convention on the Law of the Sea (UNCLOS)
United Nations Counter-Terrorism Committee (UNCTC)
United Nations Department of Peacekeeping Operations (DPKO)
United Nations Department of Political Affairs (UN DPA)
United Nations Disengagement Observer Force (UNDOF)
United Nations Emergency Force (UNEF)
United Nations Firearms Protocol
United Nations Good Offices Mission in Afghanistan and Pakistan (UNGOMAP)
United Nations High Commissioner for Refugees (UNHCR)
United Nations India-Pakistan Observation Mission (UNIPOM)
United Nations Integrated Mission in Timor-Leste (UNMIT)
United Nations Integrated Office in Burundi (BINUB)
United Nations Integrated Office in Sierra Leone (UNIOSIL)
United Nations Integrated Peacebuilding Office in Sierra Leone (UNIPSIL)
United Nations Interim Administration Mission in Kosovo (UNMIK)
United Nations Interim Force in Lebanon (UNIFIL)
United Nations International Drug Control Programme (UNDCP)
United Nations Iran-Iraq Military Observer Group (UNIIMOG)
United Nations Iraq-Kuwait Observation Mission (UNIKOM)
United Nations Logistics Base at Brindisi (UNLB)
United Nations mandate
United Nations Military Liaison Team in Cambodia (UNMLTC)
United Nations Military Observer Group in India and Pakistan (UNMOGIP)
United Nations military observer mission
United Nations Mine Action Service (UNMAS)
United Nations Mission for the Referendum in Western Sahara (MINURSO)
United Nations Mission in Angola (UNMA)
United Nations Mission in Bosnia and Herzegovina (UNMIBH)
United Nations Mission in Côte d’Ivoire (MINUCI)
United Nations Mission in East Timor (UNAMET)
United Nations Mission in Ethiopia and Eritrea (UNMEE)
United Nations Mission in Haiti (UNMIH)
United Nations Mission in Liberia (UNMIL)
United Nations Mission in Sierra Leone (UNAMSIL)
United Nations Mission in Sudan (UNMIS)
United Nations Mission in the Central African Republic and Chad (MINURCAT)
United Nations Mission in the Central African Republic (MINURCA)
United Nations Mission in the Democratic Republic of the Congo (MONUC)
United Nations Mission of Observers in Prevlaka (UNMOP)
United Nations Mission of Observers in Tajikistan (UNMOT)
United Nations Mission of Support in East Timor (UNMISET)
United Nations Monitoring, Verification and Inspection Commission (UNMOVIC)
United Nations Observation Group in Lebanon (UNOGIL)
United Nations Observer Group in Central America (ONUCA)
United Nations Observer Mission in Angola (MONUA)
United Nations Observer Mission in Bougainville (UNOMB)
United Nations Observer Mission in El Salvador (UNOSAL)
United Nations Observer Mission in Georgia (UNOMIG)
United Nations Observer Mission in Liberia (UNOMIL)
United Nations Observer Mission in Sierra Leone (UNOMSIL)
United Nations Observer Mission in South Africa (UNOMSA)
United Nations Observer Mission to Verify the Referendum in Eritrea (UNOVER)
United Nations Observer Mission Uganda-Rwanda (UNOMUR)
United Nations Office for Coordination of Humanitarian Affairs (UNOCHA)
United Nations Office in Liberia (UNOL)
United Nations Office in Timor-Leste (UNOTIL)
United Nations Office on Drugs and Crime (UNODC)
United Nations Operation in Burundi (ONUB)
United Nations Operation in Côte d'Ivoire (UNOCI)
United Nations Operation in Mozambique (ONUMOZ)
United Nations Operation in Somalia (UNOSOM)
United Nations Operation in the Congo (ONUC)
United Nations Peace-building Support Office in Guinea-Bissau (UNOGBIS)
United Nations Peace Building Support Office in the Central African Republic (BONUCA)
United Nations Peace Forces (UNPF)
United Nations Peacekeeping Force in Cyprus (UNFICYP)
United Nations police
United Nations (Political) Mission in Nepal (UNMIN)
United Nations Political Office for Somalia (UNPOS)
United Nations Political Office in Bougainville (UNPOB)
United Nations Preventive Deployment Force (UNPREDEP)
United Nations Protection Force
United Nations Protection Force (UNPROFOR)
United Nations sanctions
United Nations Security Council Resolution (UNSCR)
United Nations Security Council (UNSC)
United Nations Security Force in West New Guinea (West Irian) (UNSF)
United Nations Special Committee on Peacekeeping Operations
United Nations Special Mission to Afghanistan (UNSMA)
United Nations Stabilization Mission in Haiti (MINUSTAH)
United Nations Support Mission in Haiti (UNSMIH)
United Nations Support Office in Somalia (UNSOS)
United Nations Tajikistan Office of Peace-building (UNTOP)
United Nations Transition Assistance Group (UNTAG)
United Nations Transition Mission in Haiti (UNTMIH)
United Nations Transitional Administration for Eastern Slavonia, Baranja and Western Sirmium (UNTAES)
United Nations Transitional Administration in East Timor (UNTAET)
United Nations Transitional Authority in Cambodia (UNTAC)
United Nations Truce Supervision Organization (UNTSO)
United Nations (UN)
United Nations Verification Mission in Guatemala (MINUGUA)
United Nations Volunteers (UNV)
United Nations Yemen Observation Mission (UNYOM)
United States Central Command (USCENTCOM or CENTCOM)
United States Code (USC)
United States Naval Institute (USNI)
unitized group ration (UGR)
unity of command
unity of effort
unity of purpose
universal engineer tractor
universal transverse Mercator grid
unknown station
unlawful application of force
unlawful armed formation
unlawful combatant
unleash war
unload
unloaded
unloading
unlocking
unmanned
Unmanned Aerial Vehicle (UAV)
Unmanned Aircraft System (UAS)
Unmanned Aircraft (UA)
Unmanned Carrier Launched Airborne Surveillance and Strike System (UCLASS)
unmanned combat aerial vehicle (UCAV)
Unmanned Ground System (UGS)
Unmanned Ground Vehicle (UGV)
Unmanned Interoperability Initiative (UI2)
Unmanned Maritime Systems (UMS)
Unmanned Maritime Vehicle (UMV)
unmanned roadblock
Unmanned Surface Vehicle (USV)
Unmanned Systems
Unmanned Systems Interoperability Profile (USIP)
Unmanned Undersea Vehicle (UUV)
Unmanned Underwater Vehicles (UUV)
unmetalled
unobserved fire
unobstructed terrain
unobtainable
unopposed boarding
unopposed stream crossing
unrefuelled travel range
unrestricted burning rocket (engine)
unsecured areas
unserviceable
untenable
update
updraught
upgrade
upgrading
upheaval
uphold smth.
upon completion
upper air fallout
upper deck
upper layer
upper sideband (USB)
upstream
upward force
upward movement
upwind
uranium
urban area
urban search and rescue team (USAR)
urban target
urgent
US Agency for International Development
US Air Force Academy
US Air Force (USAF)
US Alaskan Command
US Armed Forces
US Army Air Defense Command
US Army Communications Command
US Army Community and Family Support Center
US Army Corps of Engineers (USACE)
US Army Criminal Investigation Command
US Army Development and Readiness Command
US Army Forces Command (FORSCOM)
US Army Health Service Command
US Army Intelligence Command
US Army Materiel Command (AMC)
US Army Medical Materiel Agency (USAMMA)
US Army Medical Materiel and Research Command (USAMRMC)
US Army Security Agency
US Army Signal Center
US Army Special Operations Command (USASOC)
US Army Training and Doctrine Command (TRADOC)
US Army Trial Defense Service
US Army (USA)
US Border Patrol
US Coast Guard
US Code
US Cryptologic System (USCS)
US Customs Service
US Information Agency
US Marine Corps (USMC)
US Medical Command (US MEDCOM)
US Military Academy at West Point
US National security structure
US Naval Academy
US Navy
US Pacific Command
US Patent Office
US Sixth Fleet
US Southern Command
US Space Command’s Missile Warning Center
US Special Operations Command (USSOCOM)
US Transportation Command (USTRANSCOM)
usability of forces
usable information
use of armed force
use of force
Use of Military and Civil defenseAssets (MCDA) in Disaster Assistance (UNOCHA project)
use of minimum force
user-defined operational picture (UDOP)
USS (United States Ship)
utilities restoration
utility aircraft (U)
utility clothing
utility contract
utility helicopter
utility knife
utility ship
utility truck
utility vehicle
utter defeat