Tuhia he tomokanga mō tēnei wāhanga - I te 19 o Whiringa-a-rangi, i whakawhitihia a Eden ki te Kaiwhakahaere Matua hei Kaiwhakahaere Matua Tuatoru (GSO3), me te taumata o te rangatira. I mahi ia i te Tuarua o te ope taua i waenga o Noema 1917 me te 8 Poutu-te-rangi 1918, i ngaro i te mahi i Itari (na te mea i whakawhitihia te wehenga 41 ki reira i muri i te hinganga o te ope taua Tuarua o Itari i te Pakanga o Caporetto). I hoki mai a Eden ki te Rāhui ki te Uru hei whakaeke nui a Tiamana
he mea tino tata tonu, ko te mea anake kia whakakorehia tana ope o mua hei awhina i te korenga o nga kaimahi o te ope taua o Ingarangi. Ahakoa ko David Lloyd George, te Pirimia o Ingarangi i taua wa, tetahi o nga kaitōrangapū torutoru i kii a Eden i nga hoia o mua e korero nui ana, i tuhituhi ia ki tana tuahine (23 Tihema 1917) i te riri ki tana " tatari me te kite i te koretake " i te kore e whakaae ki te whakawhānui i te whakahau ki Ireland.