How is and was relations between Chile and Argentina?
Gotta believe it ate at the Argentines that chile lined up against them?
Argentina was in a Financial Basket case chile had just privatised their social security and Uk style medical system. Argentina was envious of all the Foreign Investment in Chile and Couldn't understand their socialist way of life was sucking with 1000% Inflation. Argentina was going to attack Chile but John Paul the Great intervened. So they attacked Falklands.
Still a Bit of Animosity today... Remember at the end of World war II Argentina was the 3rd largest economy in the world.Their sel esteem was hurt.
Chile and Argentina have a history of tension. There is still some disputed territories in the south of both countries. They have fought some short but intense wars in living memory, although I believe relations are much improved these days.
Most of the good units in the Argentinian Army were on the Chilean border the entire Falklands War. It came as no surprise to them.