The second decade opened with two events neatly encapsulating the Tasmanian–Commonwealth relationship. A start was made to the Great Lake hydro project, proving the 1890s South Esk River scheme for Launceston street lighting was no one-off, and foreshadowing later battles over Lake Pedder and the Franklin River. There were portents too in the Royal Commission on Tasmanian customs leakage, which began hearings in 1910 to consider Tasmanian (and Western Australian) concerns that measures to counter their loss of revenue in agreeing to federate were only temporary. Meanwhile, led by two 'big picture' prime ministers, Andrew Fisher and William Hughes, the business of establishing a Commonwealth government which was truly national continued, administrative machinery following legislation to take over or take on critical functions. As previously, this meant a national reach with state offices, for example a Hobart presence for census and statistics (CA 1095), lighthouses (CA 1690) and domestic security intelligence (CA 906).
There were palpable reminders of Tasmania's part in the world with the arrival on the Derwent of Douglas Mawson's Aurora en route to the Antarctic (1911) and Roald Amundsen's Fram returning from his victory over the South Pole and, in some eyes, over Robert Falcon Scott too (1912). For diplomacy and defence, the orientation remained fixed on London. In line with a report by Field Marshal Horatio Herbert Kitchener in 1909 about the best means of providing Australia with a land defence, compulsory military training for males aged between 18 and 60 was introduced in 1911, the same year the Royal Australian Navy was formed. Accordingly, in that year a District Naval Office, Tasmania (CA 1547) and the Headquarters, 6 Military District, Commonwealth Military Forces, 1911–1921 (CA 1572) were also established.
Events in Europe soon impinged. Between 1914 and 1918 latent divisions in Tasmanian society were exposed by imperial patriotism, sectarianism and conscription referendums. Volunteer numbers particularly in the first years were high, stimulated when a campaign to form an all-Tasmanian infantry battalion (the 40th) paid off. Some 13,000 served overseas, more than half of whom were casualties, and 2432 were killed or died of wounds and other causes. The high cost of victory was seen immediately in the formation of the Repatriation State Board, Tasmania (CA 1590), and War Service Homes Commission, Tasmania (CA 1591), and in the appointment of a Deputy Comptroller of Repatriation, Tasmania (CA 1593). Then came Spanish influenza, killing 170 and by some estimates affecting a third of the population.