 Nyora kupfuurira kweiyi ndima - Kubva muna 1930 kusvika muna 1936, Diesen akanga ari wechipiri-mukuru paChikoro cheMigodhi cheNavy. Akakwidziridzwa kuva Mutungamiriri muna 1936. Muna 1937 akagadzwa semukuru weTatu Naval Defense District Northern Norway, uye muna 1938 akava Commanding Admiral muNorway. Akakwidziridzwawo kuva mukuru mukuru wehondo. Muna 1940 Norway yakapambwa neNazi Germany. Mwedzi miviri gare gare, Diesen akakwira ngarava HNoMS Fridtjof Nansen iyo yaakatiza nayo nyika. Ngarava yakabva kuNorway musi wa10 Chikumi, yakasvika kuTórshavn, muFaroe Islands, musi wa13 Chikumi uye yakazoenda kuUnited Kingdom kwayakagadzirirwa hondo. Kubva panguva ino Royal Norwegian Navy yakashandiswa muhondo yeAllied. Akasiya chinzvimbo chake sa Commanding Admiral muna Nyamavhuvhu 1941, pamusoro pekusawirirana nehurumende, uye akashanda muUnited States kusvika 1944. Kubva muna 1945 kusvika muna 1947 aive mukuru we Marinekommando Vestlandet. 