After the outbreak of war, the Azores quickly suffered a decline in exports to their traditional markets, particularly Britain. The British Navy was forced to reduce its presence in the waters around the Azores in favor of other theaters of war, which virtually paralyzed trade in the Azores from January 1915, after the appearance of German submarines off the archipelago.
After Portugal entered the war, the imperial submarine U-155 bombarded Ponta Degada on July 4, 1917, causing the population of the Azores to be directly affected by the war for the first time. To re-establish safe conduct in the waters of the Azores, the US created a military base in Ponta Delgada in early 1918. At the same time, a High Commission of the Republic was founded there.
Without military reinforcements from mainland Portugal, the lives of the people of the Azores deteriorated significantly. On the one hand, trade restrictions caused financial losses and, on the other hand, many farmers had to abandon their fields due to defensive measures. And as misfortune rarely comes alone, in addition to famine and war, the plague also broke out, which further disturbed public order, already shaken by internal political turmoil.
The largest influenza epidemics of the 20th century affected almost all the islands of the Azores, while the naval war still caused shortages of food and medicine. In this dire situation, local authorities were able to make the most of the limited technological and economic resources available, including working in concert with military commanders.