what, you mean like the last time the UK had a close defence relationship with Argentina, when we sold them Type 42 Destroyers and Canberra bombers?
personally i'm a fan of defence engagement as a tool of foreign policy, but i'm afraid i think that in this case it wouldn't work in our interests - we could put 30 years of work and investment into it and we could find it biting us in the arse for the sake of some poor electoral results.
distasteful as it is the current policy - that of using our economic and diplomatic muscle to strangle any re-emergence of Argentine Air capability at birth - is the most effective way of keeping this argument in the diplomatic sphere.