[1] When World War I broke out, Nepenin's role became extremely important for the commanders of the Baltic Fleet, because they depended on him for reliable information about the actions and intentions of German warships.

[1] Nepenin gained the reputation of being a very capable officer for his effective management of the signals intelligence service as well as for his ability to use available information to accurately predict the plans of the German navy.

[3][4] Nepenin's appointment was close to the start of the winter dormancy of the fleet as they waited for the sea ice in the Baltic to clear in the following spring, beginning the campaign (ice-free) season.

There were no loyal units there for the officers to use to maintain control, and all of them were either arrested or murdered by the sailors, including the base commander, Vice Admiral Robert Viren, who was killed.

But he wanted to be cautious after hearing about what happened in Kronstadt and was also asked to delay his announcement of the news to the sailors by the head of the Provisional Committee, Mikhail Rodzianko.

But his slow announcements and refusal to allow demonstrations or to meet with sailors' delegates looked bad to the men of the active fleet that supported the revolution, and they were learning of these events from another source.