The military coup that overthrew democratically-elected Iranian leader Mohammad Mosaddeqh in 1953 was conceived by the US government and carried out by its intelligence agency, a CIA document made public this week has confirmed.

Published for the first time ever on the website of the National Security Archive –a George Washington University-based research centre– the secret document confirms the US involvement that previous news reports and memoirs revealed, but that was never fully acknowledged by the American spy agency.

CLICK ON IMAGE TO ENLARGE Excerpt from CIA internal history document The Battle for Iran. Written in the mid-1970s and declassified in 2011.

“The military coup that overthrew Mosaddeqh [sic] and his National Front Cabinet was carried out under CIA direction as an act of US foreign policy, conceived and approved at the highest levels of government,” the document says (see image on the right).

An internally-written CIA document meant to recount part of the agency’s history, “The Battle for Iran” was written in the mid-1970s and partially declassified in 1981, but the section confirming the CIA’s role was excised.

The newly published document was declassified in 2011 in response a to Freedom of Information Act (FOIA) request made by a National Security archive research director Malcolm Byrne. However, Byrne waited until this week to make the document known to the public.

“I was hoping to get a more complete picture since there’s still so much that’s being withheld, but these things sometimes take a very long time,” Byrne told FRANCE 24 in an email on Monday. “My original [FOIA] request was from 2000, so it took 11 years to get this far. I decided not to wait any longer.”

The CIA confirmed that the codename for the CIA operation that ousted Mosaddeqh and installed the exiled Shah of Iran was TPAJAX. The document was posted by the National Security Archive for the 60th anniversary of the overthrow.

The text also sheds light on the thinking of US leaders at the time, their concerns over a potential standoff between British and Russian forces, and their overriding interest to maintain access to Iranian oil.

“The execution of a US-assisted coup d’état seemed a more desirable risk than letting matters run their unpredictable course,” the document states.

British meddling?

However, the section of the document that details the planning, execution and the role of the Shah has been mostly excised by the CIA. Byrne has called for a more complete disclosure of the document and other accounts of the US-orchestrated coup.

TEXT 'THE BATTLE FOR IRAN' Battle for Iran - 2013 release.pdf

“I have a pending request with the CIA for supplementary reviews, including of the “Zendebad, Shah!” document, but to date I have not received any further response,” Byrne told FRANCE 24.

The researcher said the document was significant because many details about the coup, such as the plotters and perpetrators, remain a subject of intense academic and political debate.

“The Iranian government, regularly invokes the coup to argue whether Iran or foreign powers are primarily responsible for the country's historical trajectory… whether Washington needs to apologise for its prior interference before better relations can occur,” Byrne noted.

And while an increasing amount of information is being shared, there's still pressure to keep the full story locked away.

On Monday the National Security Archive also released documents detailing British attempts to block American disclosure of intervention in Iran back in 1978.

At the time, Britain’s Foreign Office feared that a planned State Department publication would undermine the UK's standing in Iran.

But the National Security Archive queried Monday if current British meddling was not perhaps behind the stalled declassification of more key documents.