What would be the implications of a major European power leaving the European Union (EU)? Political movements in two of the most influential member states, the United Kingdom and France, have courted an EU withdrawal for decades. In recent years, however, the potential for a withdrawal has increased drastically due to the rise of two populist political parties—Britain’s United Kingdom Independence Party and France’s National Front. A British or French withdrawal from the EU would have security, economic, and legal implications both domestically and internationally. With the change in the EU, other international organizations, including the North Atlantic Treaty Organization (NATO), might assume an increased role or be subject to erosion. This thesis explores the eurosceptic movement and the causes of such sentiment. It then examines the most influential eurosceptic groups in Britain and France, analyzing their histories and comparing their goals. This thesis concludes with an assessment of the potential effects on the EU and NATO if Britain and/or France were to withdraw from the EU.

Subjects: United Kingdom; France; Britain; Great Britain; euroscepticism; European Union; NATO; United Kingdom Independence Party; UKIP; National Front; FN; EEC; ECSC; Brexit; Frexit; European elections; security; defense; international policy; domestic policy; Brussels