The EU now comprises 28 countries with majority of European non-member states seeking membership (twelve countries joined the EU in 2000s). In addition to that, most countries which remain outside are tied to the EU by economic agreements and treaties such as the European Economic Area. Within the zone of integration, there has been no conflict since 1945, making it the longest period of peace on the western European mainland since Pax Romana.
The European Union was awarded the 2012 Nobel Peace Prize in recognition of its efforts to maintain and actively foster peace within its borders as well as internationally through diplomatic means.
Even though a number of armed conflicts occurred on the European peninsula after World War II, none of them have been between members of the European Union. Most of these conflicts have taken place in the former Yugoslavia and Soviet Union.
^Herman Van Rompuy, President of the European Council; José Manuel Durão Barroso, President of the European Commission (10 December 2012). "From War to Peace: A European Tale". Nobel Lecture by the European Union. Retrieved 4 January 2014.Cite uses deprecated parameter |coauthors= (help)