What did the declassified documents reveal?

This is Declassified. Today, a declassified Central Intelligence Agency record about Project Clear Sky. This cable, dated October sixteenth, nineteen sixty-four, outlines a U.S. Air Force requirement for air samples following a Chinese nuclear detonation. You can find this document at archive.org/details/us-china-intel-CI01637. This document was released by the Central Intelligence Agency under the Freedom of Information Act. It was declassified by the Director of Central Intelligence. The document is an outgoing Department of State Telegram, classified Secret, sent from the U.S. Embassy in Taipei to multiple embassies including Ankara, Tehran, Karachi, New Delhi, Bangkok, and Saigon. The subject: Project Clear Sky. It begins: "U.S.A.F. has high priority requirement to obtain air samples in addressee countries immediately following any Chinese nuclear detonation, assuming weather and wind conditions are such as to make such sampling worthwhile. Samples would be obtained with U.S.A.F. WC-130 or B-57 aircraft operated by the Air Weather Services. Weather conditions at time of detonation will also determine whether samples should be taken and where. Hence, time of operation, countries of choice, and flight track of aircraft would be unpredictable until detonation. "Air sampling aircraft are to arrive in country once selected. Therefore, if possible, standing permission for such flights under following conditions is desired: 24 hours advance notice of arrival in country will go through Air Attaché. Precise flight track of air sampling flights within the country will be filed with flight plan. Operation will last approximately one week or less. More than one, repeat, one detonation might require additional flights. "Following airports would be used if operations were to be conducted in country concerned: Taiwan - Tainan Airbase; India - Palam; Pakistan - Mauripur; Turkey - Incirlik; Thailand - Don Muang; Iran - Mehrabad; and Teibal - Don Muang. A.I.D. will be requested through service channels to make necessary technical arrangements for support and use of these fields once standing permission for flights is obtained. "Foreign officials having need to know may, in Ambassador's discretion, be briefed on true purpose of flights in their country on secret basis. Cover story for flights would be 'weather research carried on with U.S.A.F. weather research aircraft.' Embassies requested obtain standing permission. "For Ankara: Believe these flights fall within existing technical arrangements and so no formal approach to G.O.T. required. However, appropriate G.O.T. officials may be briefed on true purpose in Ambassador's discretion. T.U.S.L.O.G. will be requested make necessary support arrangements. "For Taipei: Unless Embassy perceives objection, clearance will be arranged by A.I.D. through Joint Operations Center as in case of present Buzzard Alpha overflights, and no approach to G.R.C. by Embassy required." The Black Vault’s archive notes that this cable…

Why was this case declassified?

This material entered the public record through the U.S. declassification and Freedom of Information Act (FOIA) process. The originating source document is linked on this page so the citation chain is auditable.

Today, A Declassified Central Intelligence Agency Record About Project Clear

◆ BLUF — The short version

This is Declassified. Today, a declassified Central Intelligence Agency record about Project Clear Sky. S. Air Force requirement for air samples following a Chinese nuclear detonation. org/details/us-china-intel-CI01637. This document was released by the Central Intelligence Agency under the Freedom of Information Act.

Date: SEP 1 · 2026
Release: Declassified · U.S. public record (FOIA)
Source document: View the primary source document

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Episode notes

This is Declassified. Today, a declassified Central Intelligence Agency record about Project Clear Sky. This cable, dated October sixteenth, nineteen sixty-four, outlines a U.S. Air Force requirement for air samples following a Chinese nuclear detonation. You can find this document at…

View the primary source document

Questions about this case

What was Today, A Declassified Central Intelligence Agency Record About Project Clear about?: This is Declassified. Today, a declassified Central Intelligence Agency record about Project Clear Sky. S. Air Force requirement for air samples following a Chinese nuclear detonation. org/details/us-china-intel-CI01637. This document was released by the Central Intelligence Agency under the Freedom of Information Act.
Why was this case declassified?: This material entered the public record through the U.S. declassification and Freedom of Information Act (FOIA) process. Storyflo narrates it directly from the public release.

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Today, A Declassified Central Intelligence Agency Record About Project Clear

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