Incapable of Diplomacy

What can you say about someone who doesn't understand that when you do something wrong, you should apologize for it?

Any rational person should understand that when you bump into someone, even if by accident, you should apologize.  It is obvious if you have any inkling of what it means to be polite, civil, or hope to live in harmony with other similar people.

If you cannot comprehend this basic principle of politeness and civility, you would be completely incapable of handling much more delicate issues which occur in international diplomacy.

Thus we see that Newt Gingrich and Rick Santorum have declared themselves incapable of representing the United States in front of the rest of the world.