Europe
The UK’s decision to leave the European Union has deeply polarized the British electorate, which will continue as the reality of divorce becomes apparent and decisions are made about the contours of the future relationship. Johnson’s large parliamentary majority gives him considerable leeway to make decisions, but he will continue to confront internal divisions.
In particular, Brexit has raised questions about the longevity of British constitutional arrangements. There are increasing calls for a second Scottish independence referendum (as Brexit has qualitatively changed the question since the 2014 poll), while likely deviation between Northern Ireland and Great Britain on regulatory standards as part of the Brexit deal could intensify debate about a referendum on Irish unification.
Externally, the UK must establish a new role within Europe and address changing dynamics in the transatlantic alliance. As London embarks on trade talks with Brussels and Washington, it will struggle to secure comprehensive deals with both partners and will need to choose between their regulatory models. On foreign policy, London may feel squeezed between its ideological affinity with the continent on some issues (e.g., climate change and Iran) and its special relationship with the United States.