Final answer:
Imperialism best defines the attempt by one country to impose political control over another organized political area, involving domination in various spheres and methods like annexation or creating satellite states.
Step-by-step explanation:
The best definition for the attempt by one country to impose political control over another area that is already politically organized is imperialism. It describes a policy in which a strong nation seeks to dominate other countries politically, socially, and economically.
Imperial powers often extend control through methods such as annexation, establishing sphere of influence, or creating satellite states. The history of imperialism includes notable examples like the British Empire's control of India and the Cold War-era dynamics like the Warsaw Pact and the Truman Doctrine, where the US and USSR sought to extend their influence over other nations.