Liljestrand was commissioned as an officer in 1940 and was assigned as a second lieutenant to
Svea Artillery Regiment (A 1). Liljestrand was Senior Administrative Officer at the Coordination Department at the
Ministry of Defense from 1962 to 1963 and was promoted to colonel in the General Staff Corps in 1964. Liljestrand was Section Chief at the
Defence Staff from 1964 to 1966 and received a diploma from the Centre d’Etudes Industrielles in
Geneva,
Switzerland in 1967. He studied at the Graduate Institute of International Studies in Geneva, Switzerland from 1967 to 1968 and was commander of
Boden Artillery Regiment (A 8) from 1968 to 1969. Liljestrand was Chief of Staff of
Western Military District (Milo V) from 1969 to 1973 when he was promoted to major general. He was then head of the
Military Academy Karlberg from 1973 to 1974. Liljestrand was appointed Chief of Staff of the
United Nations Truce Supervision Organization (UNTSO) in April 1974, serving until August 1975 when he was appointed Force Commander of the
Second United Nations Emergency Force (UNEF II). The force had been organized to secure the situation after the
Yom Kippur War, and Sweden contributed a battalion. Under Liljestrand's leadership, it moved east to fill the void left by Israeli forces, which gradually withdrew from the occupied territories of the
Sinai Peninsula. He remained in the UN service until December 1976 when he left the position on his own request. For a time he was now at the command of the
Supreme Commander of the Swedish Armed Forces General
Stig Synnergren, before he was given the position of head of the Swedish National Defence College in 1978, a position he retained until he retired in 1984. Liljestrand moved to
Morges, Switzerland after his retirement to study security policy at the
Graduate Institute of International and Development Studies in Geneva from 1985 to 1991. ==Personal life==