[2] In the early 1970s Pešić became the member of the Intellectuals' Movement for the Defense and Protection of Human Rights and Freedoms, popularly known as the “Belgrade opposition”.

From 1992 till 1999 she was the president of the Civic Alliance of Serbia, and from 1993 until 1997 she was one of the leaders of the Coalition Zajedno (Together), with Vuk Drašković's Serbian Renewal Movement and Zoran Đinđić's Democratic Party.

It is worth a mention that Centre for Antiwar Action is organization largely supported by the National Endowment for Democracy, United States government institution.

[citation needed] Pešić served as national Ambassador to Mexico from 2001 to 2005, firstly for the Federal Republic of Yugoslavia, and then for its successor, Serbia and Montenegro.

Pešić was the most prominent face of the 'Blank Ballot' campaign, which targeted corruption among the ruling party officials and promoted active boycott of election.