With Brexit negotiations finally complete, Scotland could vote to separate from the UK in 2021

If the Scottish National Party wins Scotland’s parliamentary election in five months, it will be with a mandate to hold a second independence referendum.

Scotland took the idea that a lawful path to independence exists from the Québec experience, more specifically from a Canadian ruling on Québec secession. If it comes to a constitutional crisis in the United Kingdom, however, the British balance of powers may make a Canadian-style compromise impossible.

With Brexit negotiations finally complete, a process of national reckoning will soon begin that may decide whether the British union survives with its political and constitutional traditions intact.

Canada faced a similar reckoning in the 1990s after a punishing series of failed constitutional negotiations…