Dragonfly by Julia Golding (October 20th 2009--Marshall Cavendish Corp/Ccb)
"Princess Taoshira of the Blue Crescent Islands is appalled when she is ordered to marry Prince Ramil of Gerfal in order to unite their lands. And he's not too pleased, either. They hate each other on sight. So, when Tashi and Ramil are kidnapped, they fear there's no escape - from their kidnappers or from each other. Can they put aside their differences long enough to survive ambush, unarmed combat, brainwashing, and imprisonment? And will the people they meet on their adventure help them or betray them to the enemy?"
Sorry I got distracted by the pretty cover.