HONG KONG — Pity French President Nicolas Sarkozy, and be careful what you wish for. Sarkozy has taken over as the president of the once-cozy Group of Eight developed economic powers as well as the Group of 20 countries, which combines the club of old economic powers with the up and coming new ones.

It will be a wonderful opportunity for the French president to show off his schmoozing skills, which he does so well, and to collect all the international headlines as the man at the center of the world — which he hopes will aid his campaign for re-election as French president next year.

Sarkozy will quickly learn that his dream job as economic conductor of the world is likely to turn into a nightmare. Probably the only — slim — chance he has of making it work is by reducing his other powers as president of France — which would be a potential electoral disaster for him — and of persuading other world leaders to surrender their national powers.