Editing United Kingdom (section)

=== Twentieth century ===

The United Kingdom was involved in both world wars and remained a major European and Atlantic power after 1945. The post-war period included reconstruction, welfare-state expansion, decolonization, economic restructuring, and changing relations with Europe.

The country joined European institutions during the late twentieth century and later left major European political institutions in the early twenty-first century. Its politics continued to be shaped by questions of sovereignty, devolution, migration, trade, security, and the constitutional positions of Scotland, Wales, and Northern Ireland.