What term refers to the acquisition of control over a territory or country?

The term that refers to the acquisition of control over a territory or country is typically "colonization." This process involves establishing a colony in a foreign land, often with the intention of settling and exploiting resources. It historically includes the establishment of governance and societal systems by the colonizing power, frequently displacing the indigenous populations.

While "annexation" refers specifically to the formal act of adding territory to one's own territory, it usually requires recognition or approval and does not necessarily encompass the broader aspects of establishing settlement and governance that characterize colonization.

"Imperialism" is the overarching policy or ideology through which empires expand their influence, control, and governance over foreign territories, but does not solely refer to the direct acquisition of land.

"Occupation" typically describes the control of a territory by military forces without a formal claim to sovereignty, often in times of conflict, rather than the establishment of permanent control or rule that colonization implies.

Thus, the best term for the comprehensive act of acquiring control, often involving settlement, exploitation, and governance, is colonization.