In the Clinton administration, he was ambassador to Germany (1993-94) before becoming assistant secretary of state for European and Canadian affairs (1994-95). As the lead negotiator for the 1995 Dayton Ageement, he secured a peace accord for Bosnia and Herzegovina (described in his book To End a War, 1998). After pursuing negotiations in Kosovo (1998-99), Holbrook was (1999-2001) ambassador to the United Nations and then returned to investment banking. Holbrooke also was foreign policy adviser to John Kerry during the 2004 presidential campaign and to Hillary Clinton while she was a senator and during her 2008 presidential bid. Intelligent, tenacious, and sometimes combative and abrasive, Holbrooke was appointed (2009) special representative to Pakistan and Afghanistan by President Obama.