1904 During the Russo-Japanese War in February, the Japanese navy could not see the Russian warships moored in Lushun Port from the far sea and attacked them, so it tried to shoot indirectly and shell the inner channel. To this end, the Japanese navy sent a small destroyer to observe the impact point in a favorable position near the coast for calibration, and then transmitted the correct shooting instructions to the armored cruiser through radio communication in an attempt to cause a devastating blow to Russian warships in one fell swoop.

The Japanese navy did not expect that an ordinary operator in Russia broke their wishful thinking. When the Russian operator heard the information exchange between Japanese ships, he immediately realized its importance. He instinctively pressed the button of the spark transmitter of the radio communication equipment at that time, which interfered with the communication between Japanese ships. As a result, in the naval battle that day, almost no Russian warships were damaged because the correct shooting instructions of the Japanese navy were disturbed.

The earliest electronic warfare in human history has thus stepped onto the stage of war.