Leadership is one of those topics that DH and I try to incorporate into dinner discussions, biography choices, news topics, etc. It occurred to me today that I am missing the diplomacy angle. Anyone have any favorites (books, audiobooks, classes, documentaries, podcasts, etc) on diplomacy they would like to share?

This is a great topic and I'll be tuned in on this thread, because I'd also love to see some good sources on diplomacy. I really enjoyed David McCullough's biography of John Adams. The book also discusses Jefferson and Ben Franklin. It focuses on the diplomatic efforts to get Dutch and French backing for the Revolutionary war. I found myself talking about the efforts of these men with my kids just the other day, Independence Day, to be precise.

Political diplomacy or everyday diplomacy social skills by an individual....like a manager leading with diplomacy?

I took this to mean "tact and diplomacy."

For example,
... it is possible to say "No" in a nice way.
... it is possible to disagree without being disagreeable.
(By contrast, it is possible to give a backhanded compliment.)

Off of the top of my head, a specific book title doesn't come to mind however there is a plethora of information on web, including on the Skills You Need website.

Somewhat related: the negotiation books Getting Past No and Getting To Yes.

Personally, I think it's the same skill set, whether you are using a large canvas or small.

What I found interesting about the JA biography was how he felt he was personally lacking in diplomatic skills and yet managed to convince the Dutch banks to back us.

My husband is from a different country, so I practice diplomacy with my inlaws all the time, lol.

If we're looking to build our personal ability to influence, there is the classic Dale Carnegie book - How to Win Friends and Influence People.

There are quite a few books and online college-level courses in global diplomacy and/or international relations, such as this one by Coursera... I don't know how good any of them are.

Related to negotiation, not perhaps the wider topic of diplomacy: Getting To Yes is a great book (sorry I don't know how to underline titles on my iPad keyboard 😏). It intentionally spans negotiation in he home, the workplace, and in international matters and is a quick read.

https://en.m.wikipedia.org/wiki/Getting_to_Yes