He was in military training until 1918 until he travelled as an officer to newly independent Finland and fought in the Finnish Civil War together with other jägers.

After Finland made armistice with the Soviet Union, the navy took part in Lapland War in which the objective was driving off German troops from the country.

His parents were from Finland Proper; the father, Matti Vähätupa, worked as farrier in Finnish Dragoon Regiment and later he started his own business in Lappee.

He interrupted his studies in late winter 1916, when he decided secretly to join to the Jäger Movement, following example of many of his fellow students.

[1] The returned jägers took part in the Finnish Civil War on the white side, and Valve fought in battles of Tampere and Viipuri as an artillery officer.

In spring 1918, after the war was over, Valve started as trainer in newly founded Finnish Artillery School in Lappeenranta.

One reason for the quickly progressed career was the military leadership's aim to push aside the older officers served in the Imperial Russian Army, and place the jägers in the key positions.

The situation changed in 1938 when Valve became member in the committee; new plans for the Navy development were in place in 1939, but they could not be executed before outbreak of the Winter War.

Naval activity in the Winter War was low; the coastal artillery fought efficiently against the Soviet Navy and ground forces in Gulf of Viipuri.

After the war ended to bitter Moscow Peace Treaty in 1940, Finland established close relationship with Germany.

After signing the Moscow Armistice with the Soviet Union in autumn 1944, Finland was obligated to drive off the German army from its area.

Valve experienced the situation personally hard to bear; his troops took the first military action against Germany in Operation Tanne Ost in Suursaari island.

On 1 December president Mannerheim called Valve, whom he greatly respected, to take the place of Walden in J.K. Paasikivi's cabinet.