Please help!! Why do nations want to expand their territory and what are the consequences/effects of doing so?

In expansionism, governments and states expand their territory, power, wealth or influence through economic growth, soft power, military empire-building or colonialism

State-collapse anarchy, reunification or pan-nationalism are sometimes used to justify and legitimize expansionism, but only when the explicit goal is to reconquer territories that have been lost, or to take over ancestral lands. In contrast, would-be expansionists may promote ideologies of promised lands (such as Manifest Destiny), used to justify and legitimize expansionism with the perspective that targeted lands will eventually belong to the potential invader anyway, unlike claims of prior ownership.

Explanation:

i'll just take the points xd