Cold Open: This is a declassified State Department Intelligence and Research Note, dated December 29, 1967, detailing US concerns about a possible Chinese nuclear test failure. The document, released through The Black Vault, suggests that the Chinese nuclear test on December 24 may not have been a success. Provenance: The document was released through a Freedom of Information Act request and is available on The Black Vault's website. The canonical PDF is located at https://archive.org/download/us-china-intel-CI01847/CI01847_djvu.txt. The Document: To: The Secretary Through: S/S From: INR - George C. Denney, Jr. Subject: Chinese Nuclear Test May Have Been Failure Preliminary technical analysis of Communist China's seventh nuclear test, together with Peking's continuing silence about the event, suggests that the test could have been a failure. Thermonuclear Material Present. The test, which took place on December 24, 1967, in the vicinity of the nuclear test site at Lop Nor, had an estim