@badgoodDeb ..... there's an ooops on it's way from me if I've confused you ....
There are two MacMillan books that have been mentioned in this thread:
The Peacemakers - which is about the making of the Treaty of Versailles
The War that Ended Peace - which is about the build up to the WWI
The Peacemakers may also be known by another name - Paris 1919.
Here's an excerpt from the Publishers page in my copy of the ebook:
First published in Great Britain in 2001 John Murray (Publishers)
An Hachette UK Company
Copyright © Margaret MacMillan 2001
Hope that adds some clarity