"Operation Ajax (1953) (officially TP-AJAX) was an covert operation by the United States CIA in collaborating with the Pahlavi dynasty, to overthrow the elected government of Iran and Prime Minister Mohammed mossadegh and consolidate the power of Shah Mohammed Reza Pahlavi.
Rationale for the intervention included mossadegh's socialist rhetoric and his nationalization, without compensation, of the oil industry which was previously operated by the Anglo-Iranian Oil Company (which later changed its name to The British Petroleum Company) under contracts disputed by the nationalists as unfair. A particular point of contention was the refusal of the Anglo-Iranian Oil company to allow an audit of the accounts to determine whether the Iranian government received the royalties it was due. Intransigence on the part of the Anglo-Iranian Oil company led the nationalist government to escalate its demands, requiring an equal share in the oil revenues. The final crisis was precipitated when the Anglo-Iranian oil company ceased operations rather than accepting the nationalists' demands."
Continued:
http://www.thelatinlibrary.com/imperialism/notes/operationajax.html
"How Iran Was Swindled Out Of $3.2 Trillion"
"At stake is the massive Caspian Sea hydrocarbons resources prize that has been fought over since the dissolution of the USSR in 1991 resulted in three additional partners - Kazakhstan, Turkmenistan, and Azerbaijan - to the original partnership of Russia and Iran. Prior to the fracturing of the USSR into its constituent independent states, Iran and the USSR had struck the original agreement in 1921 to split all 'fishing rights' in the Caspian area 50-50. This was amended in 1924 to include 'any and all resources recovered', meaning in practical terms that all hydrocarbons resources would be shared equally between Russia and Iran."
https://www.zerohedge.com/news/2019-06-14/how-iran-was-swindled-out-32-trillion