The thing is, Sarkozy is not campaigning for the US. He will put France’s interest first, and that is why he was elected by French citizens, just as the US President isn’t elected by US voters to cater to France’s needs or desires.
You can trust Sarkozy to strongly support the United States when it does mean France will be stronger as a result, whether morally, economically, or politically. But expect him also to say “I disagree” on some issues.