1) Watershed NounLandmark, Turning Point
An event marking a unique or important historical change of course or one on which important developments depend.
The agreement was a watershed in the history of both nations.
America, The States, U.S., U.S.A., United States, United States Of America, Us, Usa - North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776; "I will kick you out from USA within two minutes".
Threaten - to utter intentions of injury or punishment against; "He is threatening me with divorce".
Though - (postpositive) however; "Though we are many, we are one family".
British Capital, Capital Of The United Kingdom, Greater London, London - the capital and largest city of England; located on the Thames in southeastern England; financial and industrial and cultural center; "I have not gone London for a long time".
What - interrogatively; "What will you do now ?".