Who is the only player to have scored for 2 different countries in the football world cup?

This from the Wikipedia article on Robert Prosineki: He is (also) the only player in World Cup history to score for two different national teams. In 1990, he scored one goal for Yugoslavia in a group match against the United Arab Emirates and eight years later he added two goals for Croatia by scoring in a group match against Jamaica and in the third place match against the Netherlands. He played in a total of nine World Cup matches, three for Yugoslavia in 1990 and six for Croatia in 1998 and 2002. One might have snapped to the fact that Croatia was formed from Yugoslavia in the wake of the reorganizations that followed the fall of the Berlin Wall and the reordering of parts of the old USSR. It isn't like he moved to Another Country and made the national team in the new location. But none of that is meant to sell him short. He was a skilled and clever midfielder whose talents were recognized early. He was named the tournament's best player when he competed with the Yugoslavian side that won the World Youth Championship in Chile in 1987. Wikipedia holds information which can be accessed by using the link provided.