I suggest you read Shakespeare and the Art of Reputation Management from Hill & Knowlton's blog. Hill & Knowlton, for those who don't know, helped Kuwait strengthen the drumbeat for war against Iraq in the first Gulf War (for an excellent case study of H&K's role, see Jarol Manheim's Strategic Public Diplomacy and American Foreign Policy: The Evolution of Influence).
While the post is aimed at corporate communication, the quotes from Shakespeare's plays are easily transformed into guides for public diplomacy itself. Some bits from the post:
"Nothing can come of nothing: speak again." -- King Lear
“O, I have lost my reputation! I have lost the immortal part of myself, and what remains is bestial. -- Othello
“If you can't get rid of the skeleton in your closet, you'd best teach it to dance.” -- Richard II
