Israel vs Palestine

From 1920 the whole region was known as Palestine (under British Mandate) until the Israeli Declaration of Independence of 1948.
Israel - Palestine under British Mandate
Is this the British trying to tell Israel what to do.  Just like they try to tell the U.S. what to do. I thought we won our independence from Britain in 1776, at least I thought that is what our founders died from.
What is this?  Imperialism