|Part of a series on
the Israeli–Palestinian conflict
The Quartet on the Middle East or Middle East Quartet, sometimes called the Diplomatic Quartet or Madrid Quartet or simply the Quartet, is a foursome of nations and international and supranational entities involved in mediating the peace process in the Israeli-Palestinian conflict. The Quartet are the United Nations, the United States, the European Union, and Russia. The group was established in Madrid in 2002, recalling Madrid Conference of 1991, as a result of the escalating conflict in the Middle East. Tony Blair resigned as the Quartet's Special Envoy on 27 May 2015.
The initiative to establish the Quartet evolved following the outbreak of the Second Intifada in September 2000 and the futile cease-fire attempts that followed. On October 25, 2001, representatives of the EU, UN and the US and Russian governments met Palestinian leader Yasser Arafat and jointly expressed support for his policy of implementing cease-fire and security reforms in the Palestinian Authority. During the Israeli incursions into Palestinian areas in April 2002, the representatives of the same four entities met in Madrid and again called for implementation of cease-fire agreements brokered by the US government before. In the same meeting, they also agreed to transform their quadripartite cooperation into a permanent forum for follow-up of the Israeli-Palestinian peace process.
James Wolfensohn, the former president of the World Bank, was appointed Special Envoy for Israel's disengagement from Gaza in April 2005. He stepped down the following year because of restrictions in dealing with the Islamic militant group Hamas and the withholding of money from the Palestinian Authority, risking its collapse.
Tony Blair announced that he had accepted the position of the official envoy of the Quartet, the same day he resigned as Prime Minister of the United Kingdom and as a Member of Parliament on 27 June 2007. The approval came after initial objections by Russia. The United Nations is overseeing the finances and security of his mission.
Tony Blair has periodically travelled to the Middle East following his appointment as Special Envoy. On a trip there in March 2008, he met with Israeli leaders to discuss recent violence. A planned meeting between Israeli and Palestinian businessmen was postponed due to recent fighting. In May 2008 Blair announced a new plan for peace and for Palestinian rights, based heavily on the ideas of the Peace Valley plan.
In an August 2009 interview, Blair said he would like to see Hamas and Hezbollah included in peace talks but under the right conditions, that religious leaders should be more involved in the peace process, and that resolving the conflict could be easier than it was in Northern Ireland.
In a speech given in Israel on August 24, 2010, Blair sharply criticised the campaign of "delegitimization" being carried out by enemies of Israel and proponents of the Palestinians, which refuses to grant Israel its legitimate right to its own point of view and self-defense. "Don't apply rules to the Government of Israel that you would never dream of applying to your own country," he said. He characterized such double standards and prejudice as being an "affront to humanity" which "it is a democratic duty to counter."
Despite the significance officially attached to the Quartet's part in promoting the peace process, many of its statements are merely repetition of previous statements and no significant changes in policy by either the Israeli government or the Palestinian Authority have occurred resulting from a Quartet meeting.
In December 2012, Palestinian officials said that Tony Blair shouldn't take it personally, but he should pack up his desk at the Office of the Quartet Representative in Jerusalem and go home. They said his job, and the body he represents, are "useless, useless, useless". 
The Quartet's meetings have been held on the following dates: