Despite what you might see a lot in the media lately the EU is not a military alliance and has explicitly no involvement in the military. So joining the EU is irrelevant on these issues.
The article mentions that sovereignty is a big issue. It should be because joining the EU means giving that up so that, I think, is the really crucial issue they should be thinking long and hard about (including, indeed, with respect to fisheries).
The article mentions that sovereignty is a big issue. It should be because joining the EU means giving that up so that, I think, is the really crucial issue they should be thinking long and hard about (including, indeed, with respect to fisheries).