"This article is first to report on the secret European five-partner SIGINT alliance Maximator that started in the late 1970s ... The five members of this European alliance are Denmark Sweden, Germany, the Netherlands, and France." tandfonline.com/doi/full/10.10…
"This European alliance has remained secret for almost fifty years, in contrast to its Anglo-Saxon Five-Eyes counterpart. The existence of this alliance gives a novel perspective on western SIGINT collaborations in the late twentieth century." tandfonline.com/doi/full/10.10…
"Crucial information about the inner workings ... of cryptographic devices sold by Crypto AG ...were distributed within the Maximator network. This allowed the participants to decrypt intercepted messages from 100+ countries that had bought compromised devices from 1970s onwards"
"Once the Maximator alliance had been established with ... Denmark, France, Germany, Sweden, and the Netherlands ... it remained stable and continues to operate today. Other countries have asked whether they could join at some stage, but such requests have been turned down"
"Certain countries were deliberately not allowed to join because within the Maximator alliance they were considered as lacking relevant (signal-/crypto-analytical) expertise and/or experience. Allegedly, these countries include Norway, Spain and Italy [and] Belgium"
"The cryptanalytical part of the cooperation involved exchanges of algorithms used in (deliberately weakened) cryptographic devices used by target countries. It was then left up to the Maximator participants ... to find out how to exploit weaknesses" tandfonline.com/doi/full/10.10…
So the Dutch helped @GCHQ break Argentinian codes during Falklands: "a specialist from TIVC travelled to GCHQ and explained how the HC500 Crypto AG devices for Argentinian naval and diplomatic communications worked; subsequent solution of the ciphers was left to GCHQ itself" 
How did Argentinians know codes were broken? Indiscreet MP, or "another account that circulates in Dutch intelligence circles is that a British pilot shot down ... carried information that could only have been obtained via compromised communications." tandfonline.com/doi/full/10.10…
Turkey wanted Crypto AG cipher machines. US wanted to give them rigged devices, Germany said no. So US then asked a Dutch agency (which didn't tell other Dutch SIGINT agencies) to sell Turkey rigged Aroflex machines. #NATOsolidarity tandfonline.com/doi/full/10.10…
#Eurospies: French DGSE's former head of SIGINT, speaking in 2016: "I told French politicians that we had to merge the BND & the DGSE. It’s the only solution. It would be a an agency with 15,000 staff ... But the French politicians never followed up." cfr.org/blog/shouting-…
