Behmen was born on 25 December 1940 in Split, Kingdom of Yugoslavia, present-day Croatia. He graduated in 1969 from the Faculty of Economics at the University of Sarajevo, where he later presented a doctoral dissertation in the field of modeling transport costs and their impact on the reproduction and development of the economy. In 1974, Behmen defended his master's degree in marketing. From 1970, he worked at the Institute of Economics in Sarajevo and at the Sarajevo State Technical University as responsible for technological and economic functions. He was also Deputy President and Chairman of the Management Board of the ŽTO Sarajevo.[2][1]
From 1978 to 1980, Behmen chaired the PO Interšped Workers' Organization. He was then appointed Assistant Professor at the Faculty of Transport and Communications.[3]
From March 2001 until February 2003, he served as Prime Minister of the Federation of Bosnia and Herzegovina entity. At the end of 2001, six citizens of Algerian origin (the so-called "Algerian Six") were accused of planning a terrorist attack on the U.S. embassy in Sarajevo. They were taken into custody in October, and the Council of Ministers revoked their citizenship in November. After a 3-month-process, the Supreme Court of the Federation of Bosnia and Herzegovina ordered their release based on lack of evidence. According to documents filed by the detainee's American lawyers in their U.S. federal court habeas action, Christopher Hoh, the then U.S. chargé d'affaires, had told then Behmen that the U.S. would cut all diplomatic relations if the men were not arrested.[4] Eventually, the Council of Ministers yielded to the demand, and the six were deported to Guantánamo Bay.[5]
On 1 August 2018, Behmen died in Sarajevo at the age of 77.[2] He was buried in Sarajevo at the Bare Cemetery on 3 August, two days after his death.[7]