Kammala jumla mai zuwa: A ranar 26 ga Janairu, 1939, an ba Miller mukamin laftana na biyu a cikin 'yan tsaron Welsh, kuma an ba shi lambar sabis na 85599. Ya yi aiki tare da Rundunar Sojan Burtaniya (BEF) bayan barkewar Yaƙin Duniya na Biyu a watan Satumba. Ya yi aiki tare da Bataliya ta 1 na rundunar, wani bangare na Brigade na 32 na Janar Janar Allan Adair's Guards Armored Division, ya kasance jarumi ne mai jaruntaka wanda ya bambanta kansa a lokacin yakin, kuma an girmama shi saboda jaruntakarsa a lokacin da bayan mamayewar Normandy a watan Yunin 1944. An ba shi lambar yabo ta Soja (MC) a watan Disamba na 1944, yayin da yake aiki a matsayin babban kwamandan kamfani a cikin 1st Battalion, Welsh Guards, tare da ambaton lura, "cewa a cikin
Arewa maso Yammacin Turai wasan kwaikwayo na ayyukan, bayan D-Day, a fuskar nauyi shelling, ya kiyaye da kewaye maza tare, ci gaba da fallasa kansa ga maƙiyi wuta, tare da cikakken watsi da ya rayuwa. "