Rubuta ci gaba don wannan sakin layi - Ya tafi Ingila a watan Yuni 1941, inda aka haɗa shi da Ofishin Jakadancin Amurka a London a matsayin Mataimakin Mataimakin Naval Attaché. A watan Satumba na wannan shekarar, ya dauki nauyin aiki a matsayin Mai Kula da Sojojin Ruwa na Musamman da kuma ƙarin aiki a kan ma'aikatan Babban, Ayyukan Hadawa (Birtaniya) a matsayin mai koyarwa a yakin amphibious, kuma an nada shi zuwa mukamin colonel a watan Disamba na 1941. A watan Yulin 1942, Hart ya shiga cikin Dieppe Operation
, wanda aka yaba masa musamman don kyakkyawan halayyar da Lord Louis Mountbatten, Shugaban Ayyukan Hadawa. Ya kasance a Ingila har zuwa Oktoba 1942, lokacin da ya koma Amurka don zama memba na Ma'aikatan Kwamandan Kwamandan, Amurka, Navy Department, Washington, D.C., a matsayin Shugaba, Tsarin Tsarin Gaba.