Under the terms of the League of Nations mandate, the island had no fortifications or military facilities and was consequently undefended, with the German forces unimpeded in their operations.

In response, Allied naval vessels were deployed to protect Nauru and nearby Ocean Island and escort shipping in the South Pacific.

Small garrisons were also established to protect the two islands, but Nauru was ultimately evacuated of most non-indigenous residents following the attack on Pearl Harbor and was invaded by the Japanese in 1942.

[2] As the islands have no harbours or anchorages, the phosphate ships were loaded by securing to deep moorings and embarking their cargo via cantilever jetties.

During southwesterly wind periods, which are common from November to March, the ships had to stop loading and sail away from the island until conditions improved.

[3] Under the terms of the League of Nations mandate system, Australia was prohibited from establishing a military or naval base or erecting fortifications on Nauru, despite the island's importance to the Australian and New Zealand economies.

On 6 December, Triona (4,413 long tons (4,484 t)) was attacked northeast of the Solomon Islands and was sunk with torpedoes after a chase in which three of her crew were killed by the raiders' guns.

Further attacks on shipping were judged impractical, as the raiders had intercepted radio messages ordering vessels bound for Nauru and Ocean Island to disperse.

[11] Weyher refused to release any of the European ethnic prisoners on board Orion, as he believed that "trained officers and crews are as much a problem for Britain as shipping itself".

[13] The two European families on the island provided the released prisoners with supplies, and sent a canoe to Kavieng in New Ireland to notify the Australian colonial government.

Orion proceeded to Lamutrik and then Maug in the Mariana Islands to overhaul her engines, Kulmerland went to Japan, and only Komet continued operations in the South Pacific.

[16] It took ten weeks to resume phosphate shipments from Nauru, and the loss of ships and damaged infrastructure led to a significant decline in output.

Komet's bombardment of the island also interfered with phosphate consignments to Japan, which caused the Japanese government to threaten to reduce the aid it was providing to Germany.

[15] In response to the attacks, Australian prime minister Robert Menzies emphasised that Nauru had been undefended under the terms of the League of Nations mandate.