Explanation From Original OP:

Context: During the cold war the CIA and MI6 (with communist Yugoslav support) launched a covert operation against communist Albania to overthrow the government with trained Albanian refugees between 1949 and 1954.

During that time, the Albanian secret police, the Sigurimi, was always one step ahead of them, frequently intercepting agents within 48 hours of entering Albania. One notable incident occurred in 1952 where multiple operatives were captured, forced to send all clear signals to other operatives. The operatives tried to send a fake “under duress” signal but the Albanian already knew about the backup codes, and forced them to send the real all clear.

All in all, over 300 CIA/MI6 agents were killed, close to 1000 anti-communist Albania refugees trained by them were killed, and 90+ Yugoslav agents were killed, with very little loss to the Albanians.

Bonus Commenter:

“The CIA told me the Sigurimi keeps executing their agents so I asked how many agents they have and they said they just go to Yugoslavia and get more agents afterwards so I said it sounds like you’re just feeding agents to the Sigurimi and then the MI6 attaché started crying”