[1] He passed studentexamen in Linköping in 1936 and received a Candidate of Law degree from Uppsala University in 1939 before becoming an attaché at the Ministry for Foreign Affairs in 1940.
[1] Rathsman served in New York City in 1942, Washington, D.C. in 1943, Buenos Aires in 1945 and was first secretary there in 1950.
[1] While serving as first secretary in Ottawa, Rathsman was en route to Stockholm on 25 July 1956 for a two-month vacation when the eastbound MS Stockholm collided with westbound Italian ocean liner SS Andrea Doria.
[2] The year after, Rathsman became Director at the Swedish Foreign Ministry and in 1959 he became embassy counsellor in New Delhi.
Before retiring, Rathsman was mediator in the Neutral Nations Supervisory Commission in Korea from 1 April 1982 to 31 March 1983 with the rank of major general.