The Question of Multipolarity

In 1969 US national security advisor Henry Kissinger wrote, ”Our deepest challenge [will be] to base order on political multipolarity even though overwhelming military strength will remain with the two superpowers.” In 1989, after years in decline the USSR fell apart and the world was left with the effective dominance of the United States of America. Since then we have seen the rise of Russia, China, India and other BRIC nations. What does this mean for the notion of multi-polarity and the really existing distribution of power in the international system of nation-states?