[3][4] Paavo Sivén adopted the name Susitaival ("wolf's path" in English) during the First World War to throw off the Czar's secret service.

His career in the parliament was short lived, as at the beginning of the Winter War he chose to apply for active duty, one of only three Finnish MPs to do so.

[5][6] During the Winter War, Susitaival served as a Lieutenant Colonel, commanding Osasto Susi in the Battle of Suomussalmi.

Despite his leadership skills and charisma, his abrasive, demanding character and a personal feud with Marshal Mannerheim, among other prominent officers, was the cause of him never advancing beyond that rank.

After the war, Paavo Susitaival retired from the Army and lived as an author in Lappeenranta, where a street is named after him.