Overthrow of Mohammad Mossadegh - Operation Ajax
Iran
1953, Aug 19
Democratically elected Prime Minister Mohammad Mossadegh nationalized Iran's oil industry - taking control from British owned Angl-Iranain Oil Company.
Britain imposed economic sanctions and a naval blocked. The CIA and MI6 used propaganda, bribery, and organized street protests to destabilize Mossadegh's government.
The Shah was placed in power to protect Western Interests
Sources
The National Security Archive
https://nsarchive2.gwu.edu/NSAEBB/NSAEBB435/
Books
All the Shah's Men
by Stephen Kinzer
Mohammad Mosaddeq and the 1953 Coup in Iran
by Mark J. Gaslorowski, Malcolm Byrne