It was just a random fucking air raid like any other.

I’d call it militarily pretty important. It was a very large air raid. It was against an unprepared target, sank important parts of the Pacific Fleet.

It wasn’t a war-winning attack, and Japan got unlucky and didn’t have the Pacific Fleet’s carriers at Pearl Harbor at the time when they needed to attack, but if you consider that Japan’s strategy, the pre-war stuff and then Kantai Kessen was basically:

1. Ensure that Japan has naval superiority over at least half of the American fleet. The Washington Naval Treaty had Japan negotiate a fleet with limits 60% the size of the American one, with the idea that the US would need to be split between the Pacific and Atlantic. (Unfortunately for Japan, the US had already broken Japanese diplomatic codes and knew that 60% was the minimum that Japan would accept and negotiated for that, but it still gave Japan an edge over the US fleet in-theater.)

2. Conduct a surprise attack, sinking a significant portion of the opposing US Pacific Fleet. This is the attack on Pearl Harbor. This was analogous to what Japan had very successfully done the last time they had fought a great power, when they hit Imperial Russia at Port Arthur:

   https://en.wikipedia.org/wiki/Battle_of_Port_Arthur

   The Battle of Port Arthur (Japanese: 旅順口海戦, Hepburn: Ryojunkō Kaisen)[2] of 8–9 February 1904 marked the commencement of the Russo-Japanese War. It began with a surprise night attack by a squadron of Japanese destroyers on the neutral Russian fleet anchored at Port Arthur, Manchuria, and continued with an engagement the following morning; further skirmishing off Port Arthur would continue until May 1904.

3. In the time purchased by knocking much of the closest opposing naval force out, conquer and secure island airbases to establish a security perimeter.

4. Wait for the Americans to conduct a prompt major naval counterstrike aimed at the area, as the Russians had in the Russo-Japanese War. Conduct an battle of attrition against this force, making use of submarines and aircraft from these island airbases to whittle it away, without having to actually face it directly. Versions of the American War Plan Orange, IIRC a decade or two earlier, did envision this prompt response, but the US had long-since decided that in an actual war, they would build up their forces to an overwhelming level and then strike.

5. Engage it near the Japanese home islands with the bulk of Japanese naval strength. At this point, the American naval force would be weakened and could be defeated in a decisive battle. Japan would win a great victory, as it had against Imperial Russia at the Battle of Tsushima.

6. As with Imperial Russia, Japan would offer fairly generous peace terms. The US, demoralized by the great loss and with a limited ability to rapidly field a major naval force in the immediate future, would accept.

In practice, it didn’t work. And it had very little chance of working, in significant part because the US was already building a lot more warships than Japan had and had a lot more ability to build more than Japan did. But the attack on Pearl Harbor was an important part of that intended strategic-level process.