The Lisbon principles were accepted at the OSCE Summit that was held on December 2-3, 1996 in Lisbon. During the summit, a statement issued by the Co-Chairs of the Minsk Group highlighted three principles for settling the Nagorno-Karabakh conflict between Azerbaijan and Armenia, namely the territorial integrity of the Armenian and Azerbaijani republics, granting of a high degree of self government to Nagorno-Karabakh within Azerbaijan, and guaranteed security for Nagorno-Karabakh and its whole population.
Armenia objected to the Lisbon Principles and found them unacceptable. “Though a blow to the Armenians, Lisbon represented the belated assertion by OSCE of the fundamental conditions to which resolution of ethno territorial disputes would be required to adhere”. When vetoing the Lisbon principles, Armenian President Levon Ter-Petrosian claimed that it predetermined the status of Nagorno-Karabakh and that this was something that should be done later, at the Minsk Conference. The Armenian delegation to the Lisbon Summit also expressed its concern regarding acceptance of the Lisbon principles, and stated that “a solution of the problem can be found on the basis of international law and the principles laid down in the Helsinki Final Act, above all on the basis of the principle of self-determination”.
Armenia also accused the OSCE Minsk Group of partiality and advocating in favor of Azerbaijan. In general, the views of many Armenians on the mediation process were similar to the following: “Armenia, which is within the USSR, is on the frontier with Turkey, which is a member of NATO and the Council of Europe. Turkey’s ethno-linguistic cousins are the rulers of Baku, not the peasantry of Arsakh, and so, Turkish, and NATO, and perhaps western sentiment in general may tend to side with the oppressors rather than with the oppressed. But with the ending of the Cold War, these distinctions and rigidly held attitudes have become somewhat blurred. However, it is one of the bitter facts of diplomatic history that great powers almost always tended to forge alliances with the large and well-placed neighbors of Armenians and to overlook rights and justice where they concern Armenians”.
However, despite all Armenia’s efforts to block the Lisbon principles, the principles were confirmed by all 53 OSCE participating states, including the USA, as a basis for negotiating the status of Nagorno-Karabakh.
 “Statement of the OSCE Chairman-in-Office”, Annex 1 to the Declaration of the OSCE Lisbon Summit, December 3, 1996, p. 15.
 Laitin, David D., and Grigor Suny, Ronald, “Armenia and Azerbaijan: Thinking a way out of Karabakh”, Middle East Policy, Vol. 7, No. 1, 1999, p. 164.
 Nishimura, Megumi, “National Self-determination and the International Community in the Transcaucasus: Inconsistency and Domestic Response”, Central Asia and the Caucasus, Vol. 5, No. 11, 2001.
 “Statement of the Delegation of Armenia”, Annex 2 to the Declaration of the OSCE Lisbon Summit, December 3, 1996, p. 16.
 Walker, Christopher J., Armenia and Karabakh: The Struggle for Unity (Minority Rights Publications, 1991), p. 71.