loan mechanism was agreed. The crisis also spurred consensus for further economic integration and a range of proposals such as a European Monetary Fund or federal treasury. The European Union received the 2012 Nobel Peace Prize for having "contributed to the advancement of peace and reconciliation, democracy and human rights in Europe." The Nobel Committee stated that "that dreadful suffering in World War II demonstrated the need for a new Europe [...] today war between Germany and France is unthinkable. This shows how, through well-aimed efforts and by building up mutual confidence, historical enemies can become close partners." The Nobel Committee's decision was subject to considerable criticism. On 1 July 2013, Croatia joined the EU, and on 1 January 2014 the French Indian Ocean territory of Mayotte was added as an outermost region. 2016–2020: Brexit On 23 June 2016, the citizens of the United Kingdom voted to withdraw from the European Union in a referendum and subsequently became the first and to date only member to trigger Article 50 of the Treaty on European Union (TEU). The vote was in favour of leaving the EU by a margin of 51.9% in favour to 48.1% against. The UK's withdrawal was completed on 31 January 2020. 2020–2022: Impact of the COVID-19 pandemic After the economic crisis caused by the COVID-19 pandemic the EU leaders agreed for the first time to emit common debt to finance the European Recovery Program called Next Generation EU (NGEU). 2022–present: Impact of the Russo-Ukrainian War On 24 February 2022, after massing near the borders of Ukraine, the Russian Armed Forces undertook a full-scale invasion of Ukraine. The European Union imposed heavy sanctions on Russia and agreed on a pooled military aid package to Ukraine for lethal weapons funded via the European Peace Facility off-budget instrument. Likewise, neighbouring EU member countries received a mass influx of Ukrainian refugees fleeing the conflict over the course of the first weeks of the war. The conflict exposed the EU energy dependency on Russia, deemed as a supplier "explicitly" threatening the EU. This development injected a sense of urgency in the switch towards alternative energy suppliers and further development of clean energy sources. Structural evolution See also Timeline of European Union history Enlargement of the European Union History of the euro History of the Common Security and Defence Policy List of European Councils List of presidents of the institutions of the European