In 1917, he came to Finland with the German U-boat SM UC-57 to fight on the side of the Whites during the Finnish Civil War.

During the Continuation War he took part in the re-capture of Vyborg and later in the Battle of Tali-Ihantala, where he distinguished himself by managing to halt the Soviet advance in his sector.

The regimental commander reported the incident to Vihma, who fully approved of the actions of the officer in charge, Captain Niilo Ahonen.

In 1946, the Supreme Court of Finland found Ahonen guilty of 46 counts of involuntary manslaughter and sentenced him to one year in prison.

Confirming Vihma's involvement, the ruling stated that superior orders had been accepted as a mitigating circumstance.