[6] Relations continued to deteriorate during the First World War (1914–1918) during which Nyasaland was a key route to supply and reinforce British forces in East Africa.
[1][6] Smith implemented unpopular measures such as the centralisation of powers previously held by the chiefs, calling for Africans to enlist in the British forces and requisitioning food from areas already facing shortages.
[6] One of Smith's first actions during the war was to commandeer all ships on Lake Nyasa and launch an attack upon the German vessel Hermann von Wissmann at Sphinx Hafen.
[1] On 20 August 1914 Smith mobilised the Nyasaland Volunteer Reserve which defended the colony from a German invasion and later served elsewhere in the East African campaign.
[7] After the 1915 Chilembwe uprising, which he moved swiftly to quash, Smith noted that it marked "a new phase in the existence of Nyasaland" and established a commission to investigate its causes.
[1][8] Smith was granted responsibility for administering the former German East African territories occupied by British forces advancing from Nyasaland and sent many of his civil servants into these areas.
[1] After the war a large number of ex-servicemen migrated to Nyasaland and Smith took measures in 1918 to limit the leasing of crown land to these men, as he determined that it was needed for the resettlement of Africans evicted from their farms.
However, by Smith's retirement the government's plans for the Dona Ana Bridge in neighbouring Mozambique, that would allow rail communications to the port of Beira, were well progressed and a railway laid to Lake Nyasa.