The definition of a diplomat is:
"Doing nothing and saying nothing nicely."
A proficient Diplomat stands his or her own ground without ever making someone else feel inadequate. A good diplomat knows when to speak up and when to stand down.
Diplomats speak to everyone at the party. They know how to "work the room." Talking to each person for 5 minutes, then smoothly excusing oneself from the conversation and moving on to begin a conversation with the next person (or group of people) is a skill. Most people have to learn in their own style how to do it, then practice it until it is effortless.
Eye contact, handshaking, listening, being positive, appeasing and pleasing yet strong, beginning then ending a conversation are key skills in "working the room."
Practice this skill at your next party. Talk to people you do not know. You never know, you may make a new BFF. Enjoy!