Starting a war
> It would also be particularly stupid of the Argentinian military to assume that a major NATO military, that you were about to start a war with, wouldn't be spying on you
Ah, but the Argentinian state (led by a military junta) didn't think it was starting a war, because it was interpreting actions of the UK Foreign Office with respect to the Falkland Islands in a particular way, and thus thought there would be diplomatic protests, disputed declarations in the UN, yadda yadda, but that they'd end up with de facto sovereignty over Las Malvinas in addition to the de jure sovereignty that they claimed, and still claim to this day. Even the dimmest General (and you don't get promoted to General by being dim) would know that Argentina couldn't win a war with the UK.
And indeed, Argentina didn't lose one. As I've said before, it wasn't a war in 1982, it was (as ex-RAF Egghead & Boffin, above) correctly describes it, a "conflict", a military Operation codenamed Corporate by the UK MOD. 75 years after VE Day isn't a good time to forget the difference between limited military conflict and total war.