Navaleye,
It would look bad if the UK sank some fishing boats, or a cruise ship etc. Also, do we have sufficient assets to detect potential invasions from all directions - including the air?
I believe that Argentina are extremely unlikely to succeed, which is why I believe it to be foolish to even attempt an invasion. One thing on their side is the fact that the very few assets that we have are currently focussed else where.
I do feel that Argentinian politicians may not have any option though.