The Quartet of Middle East peacemakers is a body comprised of four nations and international bodies - the United States, Russia, the European Union and the United Nations - which are involved in working toward a peace agreement between Israel and the Palestinians.

The Quartet was established in Madrid, Spain, in 2002 as a response to escalating violence between the two sides at the height of the Second Intifada.   Tony Blair became the Quartet's Special Envoy to the Middle East in June 2007, on the same day as he ended his 10-year tenure as British prime minister.   The group has been involved in consistent peace-making efforts, and is the author of the Road Map to Middle East Peace – a three-stage plan aimed at ending the decades-long Mideast conflict.   In March 2010, the Quartet issued a statement condemning Israel's decision to build 1,600 new housing units in East Jerusalem and the West Bank, as well as announcing support for the reaching of a peace treaty by March 2012.   The statement was greeted unenthusiastically by the Israeli government and within hours of the announcement, Foreign Minister Avigdor Lieberman accused the Quartet of “ignoring'” Israeli efforts for peace over 16 years of negotiations, and of forcing an artificial timetable for the peace process.   Palestinian Authority President Mahmoud Abbas welcomed the Quartet statement, however, describing it as “very important.”