There’s been quite an uproar over the past week regarding the latest Pentagon document leak. While much of the attention has been focused on material dealing with Ukraine, another U.S. ally is not happy about alleged American snooping on its internal affairs: South Korea.

Responding to the allegations, South Korean Democratic Party leader Lee Jae-myung said, “If it is true that they have spied on us, it is a very disappointing act that undermines the South Korea‑U.S. alliance, which is based on mutual trust.”

What the South Korean minority party leader may not be aware of is that his own government has a history of spying on his U.S. counterparts in the American Congress. The evidence comes in the form of a partial declassified FBI memo dated December 5, 1975, obtained by Cato via a Freedom of Information Act request.

The exact confidential source of the information remains classified nearly 50 years later, but the source was not only aware of FBI interest in the South Korean espionage and influence operations, but was seeking information from the Bureau as well–specifically the names and positions of the South Korean intelligence officers operating against Congress, suggesting the source may have been an intelligence or law enforcement officer from another agency or department.

The late Senators Strom Thurmond (R‑SC) and James Eastland (D‑MS) and Representative Otis Pike (D‑NY) were all involved in the drama, though to what degree is difficult to say given the still ridiculously high level of redaction in the five-page memo. The memo reveals the FBI’s Washington Field Office (WFO) was investigating at least some individuals mentioned by the confidential source. Whether any further action was taken by WFO in connection with this case is not known to the author.

These episodes–old and new–are just reminders that allies spy on or try to influence each other nearly as much as they do on their adversaries.