Whakaotihia te rerenga e whai ake nei: I haere ia ki Ingarangi i te Pipiri 1941, i reira i whakauruhia ai ia ki te Embassy o Amerika i Ranana hei Kaiāwhina Naval Attaché. I te marama o Hepetema o taua tau ano, i whakawhiwhia ia ki nga mahi hei Kaitirotiro Moana Motuhake me te mahi taapiri i runga i nga kaimahi o te Tumuaki, Whakawhanaunga Whakawhanaunga (British) hei kaiwhakaako i te pakanga amphibious, a ka tohua ia ki te taumata o te koronel i te marama o Tihema 1941. I te Hōngongoi 1942, i uru a Hart ki te
Operation Dieppe, i tino whakamoemititia ai ia mo tana whakahaere tino pai na Lord Louis Mountbatten, Tumuaki o nga Mahi Whakakotahi. I noho ia ki Ingarangi tae noa ki te Oketopa 1942, ka hoki mai ia ki te United States ki te noho hei mema o te Kaimahi o te Kaihauturu-i-te-te-kaihauturu, US Fleet, Navy Department, Washington, DC, hei Tumuaki, Future Plans Section.