In 1937, he entered the International Training College in London, England, as a cadet in the Enthusiasts session, becoming an officer in 1938.

[1] As General, he headed an International Leader's Conference of The Salvation Army in Berlin 1984 and a Holy Land Congress a year later.

Wahlström was honoured by Rotary International with a Paul Harris Fellowship in 1987 and was made a commander of the Order of the White Rose in Finland in 1989.

[1] General Wahlström has also been credited with promoting the internationalization of the Salvation army, and furthering its ecumenical dialogue.

He sought to find the "balance between denominationalism and ecumenism" and to "have an open mind and a sincere will to co-operate with Christians of other Churches".