densely populated (densely-populated) area (region) / territory / country

acquisition of land / territory

enemy-held territory

hostile territory

incursion into enemy territory

state territory

swift entry into hostile territory

territory transfer

insert special forces teams into enemy territory

aerodrome adjacent territory

absorption of territory

armor territory (terrain)

Russian-held territory

take back territory

uncharted territory

arid region

army readiness region

flight information region (FIR)

geostrategic region

strategic region

air defense region (ADR)

depot distribution region

ensure peace and stability in the region

hydrodynamic lubrication region

irrotational region

stagnation region

dead region

vorticity region

search and rescue region

simply coherent region

simply connected region

transition region

confusion region