In a phenomenon dubbed diversification of European security, NATO has come to be responsible for "hard" threats while the European Union has taken a greater role in "soft" threats, including peacekeeping in the western Balkans.[4] The 2007 Treaty of Lisbon also has furthered defence integration within the EU.[4] This has led to support for a European Defence Union, which would be a step higher in collaboration than the current Common Security and Defence Policy.[5]