Sport: A unifying factor?

I've usually taken the attitude that sport can unify people from different backgrounds, but seeing as they are unified mainly in hating a different, equally arbitrary, group, I wonder if there is actually any benefit in the 'artificial' unity.

When this is applied across countries, (England v Germany) for example, it merely seems to magnify differences which already exist. More interesting, therefore, is the impact of the success of a national sports team on a nation which is internally split. In this context, the African 'Cup of Dreams' is quite interesting.