In 1997, Meleșcanu founded the Alliance for Romania (Alianța pentru România) party, together with several former members of the PDSR (Mircea Coșea, Iosif Boda, and others).

He is a professor at the Faculty of Political Sciences of the University of Bucharest, and has written a substantial number of works and scientific publications dealing with international law and diplomacy.

On February 27, President Traian Băsescu appointed him for the SIE position vacant after the former director Mihai Răzvan Ungureanu's ascension to the post of Prime Minister.

[2] In November 2014, following the resignation of Titus Corlățean as a result of problems with voting in the Romanian diaspora during the first round of that year's presidential election, Meleșcanu was appointed foreign minister.

On 6 June 2019, The National Anticorruption Directorate (Romanian: Direcţia Naţională Anticorupţie (DNA)) announced that it has launched a criminal investigation in the matter.

[5] [6] Meleșcanu is a Member of the Advisory Board of the Global Panel Foundation, based in Berlin, Copenhagen, Prague, Sydney and Toronto, which works behind-the-scenes in conflict areas around the world.

Meleşcanu published a wide range of scientific papers and publications related to international law and diplomacy.