the process of becoming isolated — when an organization, person, or country is cut off from others (often used with suru: 孤立化する).
企業の不祥事が続き、次第にその会社は孤立化していった。
Following repeated scandals, the company gradually became isolated.
外交方針の誤りが国の孤立化を招いた。
A mistaken diplomatic policy led to the country's isolation.
いじめが原因で、生徒がクラスから孤立化することがある。
Because of bullying, a student may become isolated from the class.