He is a Polish mathematician, alpinist, politician and was the vice-president of the European Parliament's Foreign Affairs Committee from January 2007 until mid-2009.
After the fall of communism in 1989, Janusz Onyszkiewicz became a member of the Polish Sejm. He served all subsequent terms from May 1989 until 2001. In the spring of 1990, Mr. Onyszkiewicz became the first civilian vice-ministers of defence in the communist-dominated period.
Subsequently, Janusz Onyszkiewicz was Minister of Defence twice, in the cabinets of Hanna Suchocka (1992–1993) and Jerzy Buzek (1997–2000).