Haven't tried it myself but I think you just select a nation and the points you accumulate go towards that nations standings but you can choose a new team each time you play.
Algeria is still leading so that must be what happens.
the smaller the population (or the supporter base), the more points you'll accumulate for the nation of your choosing...
you just choose a nation to represent.... say you choose Australia, you'll get points for Oz regardless of the team you use