Answer:
When a country extends its power by taking over countries through diplomacy or military actions.
Step-by-step explanation:
A trading agreement between 2 or more countries - This is an FTA.
When countries rulers are Kings and Queens - This is a monarchy.
When a country extends its power by taking over countries through Diplomacy or Military Actions - This is imperialism. A real-life example would be the British Empire.
When countries join in an Alliance - This is a coalition.