VIENNA -- "Bright and fierce and fickle is the South," wrote the English poet Alfred Lord Tennyson, "dark and true and tender is the North." He wasn't, as far as we know, thinking particularly of Europe when he penned those lines in 1850. But the idea that northern and southern European countries have fundamentally different characters is one that has persisted through the centuries.


Within the European Union, the differences between north and south are growing. This is a direct consequence of the EU's plans for expansion. As things stand, Austria and Finland will join the EU next January, and Sweden and Norway are holding referendums this month to decide if they will follow suit. The next countries lined up for admission are the Czech Republic, Hungary, Poland and Slovakia.


Some of these countries might best be defined as central European, but from the perspective of the EU's southern members that is not really the point. For the southerners, the problem with the EU's expansion is that the union could soon have 20 members, of which 15 would be non-Mediterranean.


This, the southerners fear, could have two consequences. First, under the EU's system of qualified majority voting, a "northern bloc" dominated by Germany, the Benelux countries, Britain, the Nordic states and the new central European members could outvote the southern countries on many important issues. The focus of EU attention would center on boosting the economic performance and political stability of former communist countries.


That would mean investing tens of billions of dollars in the former communist east and reducing the amount of money allocated to the south. Greece, Portugal and Spain have received enormous financial benefit from being full EU members, and naturally they want the good life to continue.


The second consequence is that the EU's foreign and security policies may tend to concentrate on areas such as Russia and other former Soviet republics. The southerners fear this may mean the EU will neglect urgent problems in the Mediterranean, Middle East and northern Africa.


Above all, as French President Fran?ois Mitterrand and Spanish Prime Minister Felipe Gonzalez made clear last month, the EU may fail to come up with a solution to the Algerian problem. Between 10,000 and 20,000 people have died in Algeria's civil war since January 1992, and Europe's Mediterranean countries are haunted by the specters of Islamic fundamentalism, mass immigration into southern Europe, and racial and religious unrest.


Other "southern" crises are looming, too -- notably northern Africa's population explosion, which is likely to undermine living standards, increase unemployment and create a new generation of student graduates discontented with their own societies and bearing a grudge against Europe. Yet when Spain's senior EU commissioner, Manuel Marin, recently proposed a five-year, $7 billion aid package for northern Africa and the Middle East, he received a relatively cool response from the EU's northern states.


Coping simultaneously with the eastern and southern challenges will not be easy for the EU. If Europe's eastern question looked more important from 1989 to 1991, surely now the southern question is equally urgent. The "tender North" must listen more closely to the "fickle South."