Ambitions are declared at the end of week 1, during the introduction challenge. Some ambitions will earn the approval of your own (or other) nations, or will earn friendship or respect points from certain delegates.
It is possible to declare a public and private ambition, if they are different. This requires lying to the whole summit, and if you get caught at it people won't be thrilled with you.
The same as before, but reversed.
End up with more power and wealth than you had before. Several of the more ethical delegates will gain rivalry points if you publicly declare this to be your ambition.
Serve your country
Requires solving your nation's particular dilemma. You will get extra approval from your nation for this. Arland is impressed with your dutifulness, Hise slightly less so. On average the nations gain ++ approval for this ambition. It can also be chosen with a different private ambition, with no penalty.
Creating (or strengthening) an alliance for your nation. Does not necessarily require your own marriage. Increases nation approval by +. Lisle, Zarad or Gisette may gain points in respect or friendship, for the MC of the relevant nation.
World Peace, and possibly a swimsuit pageant. See Katyia's Legacy for details.