IMO the key document available from the negotiations on the unification of Germany and whether the Unified Germany would be Neutral or a member of NATO was the letter from baker to Kohl on the topic of Germany's NATO membership.
The two options then were: (a) A united Germany as a neutral country (b) A united Germany as a NATO member AND that NATO would not move " an inch more eastward"
Have a read of the entire letter because there is a vast difference between what was documented then and an 84 year old's recollection of it some 24 years later, IMO.
