In 1981, he embarked on a United Nations mission to the volatile region of Cyprus, a commitment that was followed by another overseas assignment in 1988 when he assumed command of a UN battalion in Lebanon.

Throughout the 1990s, Hederstedt held various significant roles within the military, including serving as the brigade commander of the Life Guards Brigade, the commander of the Western Army Division, the deputy chief of the operations leadership for international operations, and a military expert at the Ministry of Defence.

He was educated at the Swedish Infantry Cadet and Officer Candidate School and became second lieutenant in Älvsborg Regiment after graduating from the Royal Military Academy in 1966.

In Lebanon, Hederstedt conducted many negotiations on various levels with several of the factions (e.g., PLO, PFLP, Hezbollah, Black September, Amal, etc.

He also conducted fact-finding trips to troublespots, including Cyprus, Kuwait, Iraq, Iran, and the Middle East (Israel, Gaza, and Lebanon).

[4] Hederstedt was promoted to major general in 1996 and was appointed International Operations Commander at the Swedish Armed Forces Headquarters.

[4] Hederstedt accompanied Björn von Sydow on several trips to Angola, Namibia, South Africa, Kenya, Morocco, Congo, Uganda where they met with government leaders and members of opposition parties.

During his time as Supreme Commander, he developed and set the basics of a new organisational and technical worked based structure of the Swedish defence.

In December 2004 Hederstedt got the mission of the Swedish government to coordinate and organise the aid work in Thailand after the Tsunami disaster.

[8][9] He was elected as a member of the board of the Swedish Childhood Cancer Fund (Barncancerfonden) in May 2005[10] and served as its chairman from October 2005 until June 2010.