Upon returning to Bosnia and Herzegovina in 2007, Arnaut served as an advisor on constitutional and legal affairs in the Cabinet of then-member of the
Presidency of Bosnia and Herzegovina,
Haris Silajdžić. In 2010, he was appointed Ambassador to Australia and New Zealand. After completing his diplomatic mandate, he returned to Bosnia and Herzegovina and joined the political party
Union for a Better Future (SBB BiH). In 2014, he briefly served as an advisor at the
Ministry of Security, and later that year at the
2014 election was elected to the
House of Representatives of Bosnia and Herzegovina. Four years later, he secured a compensatory mandate in the same institution and also served as a member of the
Parliamentary Assembly of the Council of Europe. In December 2019, Arnaut resigned from all party positions due to his opposition to SBB BiH joining a coalition with the
Party of Democratic Action (SDA) and
Democratic Front (DF). He subsequently left the party and joined
Our Party, with which he won a seat in the
House of Representatives of the Federation of Bosnia and Herzegovina in the
2022 election. In 2023, he was appointed Ambassador of Bosnia and Herzegovina to Germany. == Private life ==