I think that nationalism is the nasty thing that often gets confused with patriotism. Nationalism is an aggressive, anxious thing, which depends for its existence on comparisons with other nations - 'my country right or wrong', 'my country is better than yours', etc - yuck. Patriotism I see as not only positive but completely natural, and probably instinctive - love for the people and landscapes of one's country which makes up 'home', that one will fight to protect but not fight to impose on others. As a patriotic Englishman I would say good examples of each are to be found in our history - when we went and took over bits of Africa we showed the worst kind of Nationalism with its attendent racism, and when we defended our country against Napoleon and Hitler we showed superb and completely neccessary patriotism, without which we would probably not exist.

I also think that a great way to turn patriotism into aggressive and unpleasant nationalism is to label it wrong and nasty and try to suppress it, as some people on this thread seem to be advocating. It is too powerful and instinctive to be uprooted by well meaning lefties, and needs to be channelled into harmless and creative avenues - excellence in a nation's arts, sports, public and private rectitude and honesty, public service, conservation of a country's beloved natural landscapes and so on. If it is repressed you get football hooligans and similar filth, who think urinating on a Portugese footpath is some kind of victory for England.