NATO has never had a declaratory policy. Instead it has explicitly preferred thus far to rely on the three distinct declaratory policies of its nuclear member-states, despite their contrasting conditions-for-use.
2018
The Iran Deal: A Conversation Between Close Allies
The U.S. is at odds with one of its staunchest allies. Why?
US Nuclear Posture Review
This is the full version of the US Nuclear Posture Review, first published on 2 February 2018 on the DoD website, and then apparently removed the following day.