Of course, this will also involve the modification of the nuclear bomb, which has been installed* and has only four countdown settings, namely 1 hour, 30 minutes, 15 minutes and 5 minutes. But the 5-minute countdown is still too long, and it is likely that the nuclear bomb has not exploded yet, and the submarine has already been wiped out by the enemy's fleet fire. This will inevitably make the whole program more cramped and difficult. As a matter of fact, it is not wise to rush to launch such an attack when the mechanism of the transmission of the explosive power of a nuclear bomb in a different medium is still completely unclear. However, Japan did not have time, even if Konoe Fumiro was still talking about "strategic" and "forward-looking", and deliberately downplayed the threat of Chu Tingchang, reducing it to a secondary direction of the battle level threat, but in essence, it was precisely because Chu Tingchang almost cut off the empire that the decision-makers of the Japanese empire were forced to increase the stakes far beyond the Tojo era. What is hateful is that for the time being, it is not possible to use a nuclear bomb against Chu Tingchang.

The reconnaissance planes found a large merchant fleet and a destroyer detachment in San Francisco, as well as as four aircraft carriers, but judging by the length, it may be some kind of "special aircraft carrier" for the improvement of merchant ships.

Further reconnaissance revealed that the US military fleet was training take-off and landing off the coast from Los Angeles to San Diego, and today's subjects were night landing and night radio navigation. A large number of novices are piloting the new Hellcat fighter jets, and they are in full swing training. The reason why the coastal training was chosen was to prevent the failure of navigation and the failure to find the aircraft carrier, and to land at the nearest naval airfield.

It is impossible for coastal air defense radars to detect a single small reconnaissance aircraft. Japanese planes followed the target at a low speed. It is roughly determined that this fleet, which has 2 to 3 large fleet aircraft carriers, has returned to the San Diego military port, which was once the home port of the US Pacific Fleet, so the German intelligence is still reliable, and some of the US training ships are indeed scattered in San Francisco or Los Angeles, but the main force is definitely here. What people didn't expect was that in addition to the formidable fleet at Pearl Harbor, the U.S. military also hid a huge combat power here, not to mention that they also had a fleet against Germany on the east coast. People just don't want to accumulate high levels at home and play an arms race.

The plane flew almost over the fleet and sneaked into the harbor. The lights in the harbor are enough for those warships that have not turned on the lights to appear, and looking at the warships docked neatly at the berths, the size of the fleet here alone is already comparable to half of the combined fleet. And not just aircraft carriers, but a large number of destroyers and cruisers that followed.

The back-seat observer used a camera to film the scene below, and as shown on the map, the entrance to the harbor was narrow. The U.S. Navy's choice of military ports seems to be inclined to such a narrow entrance bay, which will make it more difficult for ships to enter and leave the port, but it will also bring many benefits to defense.

The entrance is about 700 meters wide, winds north, and then turns 90°, the larger the ship, the more inward. Of course, it is impossible to see the details too clearly, but unfortunately, you can't come and see them during the day.

Of course, the reconnaissance was insufficient, the fuel was not crowded, and the pilot had to choose to return, and then came the hardest part - to return to the vast sea and find the submarine. There are many uncertainties in this, there are very few islands off the coast of California, only a few reefs and lighthouses can provide references, once missed, it means that the sea area cannot be found, and the submarine at dawn, on the surface of the sea, is just a thin shadow, easily hidden by the golden waves under the rising sun, and once the wind blows, it will dive into the sea.

At four o'clock in the morning, the plane lowered its altitude and waited for dawn. Unfortunately, a Caterina anti-submarine aircraft, which came out early in the morning to tame the sea, saw a low-flying Japanese reconnaissance aircraft. The American pilots flew an average of 60 hours, and were not sure if it was their own plane, but out of curiosity, they decided to take a closer look.

It was only when the sky was slightly brighter that the machine gunners on the American plane could see through the binoculars that it was a Japanese plane, and the sun markings on the plane were not even disguised (the mission was hasty). Caterina was a very slow plane, but just enough to catch up with the slower reconnaissance plane.

The slow pursuit of 45 minutes was enough for the Japanese to sort out the situation and send a report, specific to the size of the enemy and the level of the port garrison, the Japanese used the codebook issued with the order, of course, it was impossible to decipher. Captain Kanda's first reaction after receiving the telegram was to dive immediately, he knew that the reconnaissance plane was not saved, and now he had to save himself first, if the US military was allowed to see the submarine, then the mission intent (although he himself did not know what kind of mission this reconnaissance would eventually lead to) could be exposed.

After approaching the reconnaissance aircraft, the anti-submarine aircraft fired at the target using the weapons in the rotating machine gun turret, and the Japanese aircraft immediately counterattacked with a recoiler machine gun. In this firepower competition, the Japanese planes of course had an absolute advantage, and the pilots kept trying to hide in the enemy's shooting corners, but the stupid anti-submarine planes had almost no firepower corners.

In the end, the reconnaissance plane was beaten and destroyed. After the pilot started*, he chose to crash into the sea, and the backseat pilot issued the last words before he died: We will repay the country with death. Probably because the time was too rushed, it was not encrypted against the codebook. The plane was blown to pieces on the surface of the sea and soon sank to the bottom of the sea.

The US plane quickly cruised around, and at 7:15 a.m., it found a suspicious periscope, but soon the periscope disappeared, and in the subsequent report, the US pilot judged that it was a reconnaissance or sabotage activity of a large Japanese submarine, because when they saw it, it was flying from east to west, and it was obviously completing the mission and was returning home, and in the direction of its return, a suspicious submarine was discovered.

It is not the first time that a Japanese submarine has appeared on the west coast, but this time the US intercepted the Japanese radio communication, but unfortunately it could not be cracked. In fact, this telegram, which is encrypted with a one-time password, cannot even be deciphered by 419, but from the length of the telegram text, it still leaves a lot of information and can make some judgments.

Qin Xiaosu has been staying in the Chu Tingchang Headquarters, serving as liaison and intelligence analysis. Judging from the length of the text, he judged that it was a substantial telegram.

Under what circumstances, the plane would desperately send out a message dozens of minutes before it was shot down, without using a simpler voice communication, obviously the content was very important and had to be kept secret, and finally the Japanese used suicide, which they are best at, to keep the secret. Of course, there are enough horse's feet that leak out of it, even if it is impossible to decipher the message directly.

Qin Xiaosu's personal judgment that the next move of the Japanese Navy may be on the west coast (combined with US military communications, judging the position). Given that the Japanese naval fleet was unlikely to skip Hawaii directly to carry out the operation, he judged that what was coming was probably a suicide operation with a submarine carrying a nuclear bomb. Even the location, he can guess the same as ten, there are only four targets to choose from, which are Seattle, San Francisco, Los Angeles or San Diego, and from the area where the plane was shot down, he prefers the last few options. The sneakiness of the Japanese made Qin Xiaosu sure that they would have a major operation, of course, it could not be to go to the American forest to set fire, if you add their madness, it is not difficult to judge that they will directly use the only nuclear bomb to attack.

His opinion was immediately agreed by Cheng Dayang and the political commissar, but now 419 is facing a dilemma. The source of the Japanese nuclear bomb is undoubtedly Kasuga Maru, and apparently 419 was not in the East China Sea, and the Japanese secretly carried out a salvage, and it was much more successful than the previous two years. The immediate task now is obviously to rush to the East China Sea quickly and disrupt its salvage process, so that this Japanese attack can only be resigned?

When this dilemma occurs, Lin Xiuxuan's opinion becomes particularly important, and many times 419 needs him to make key decisions and take responsibility. However, after his plane landed in northern Thailand, floods washed away roads and delayed for several days in areas where communication was difficult. At this time, new situations appeared one after another, and everyone was waiting for his opinion.

The first thing he did when he returned to Chief Chu's headquarters was so tricky.

Of course, after thinking about it all night, he felt that the nuclear bomb going to the United States could be ignored. The Japanese dared to do so, only based on their historical understanding, believing that a display of firepower blocked at their doorstep would be enough to force their opponents to submit, just as they did against Russia and the Qing Dynasty, but it would obviously only be counterproductive to the United States. Therefore, the top priority at the moment is to quickly cut off Japan's access to more modern military technology from the Kasuga Maru.

Of course, to carry out such a mission, Lu Qingshan must be involved, because he is the most professional diver on the 419. Therefore, 419 cannot leave the Gulf of Thailand for the time being, and needs to wait for the landing team to return.

Lin Xiuxuan's judgment was a little risky (Roosevelt would give in and withdraw from the war for the time being), but it was still very convincing on the whole. At present, what the Japanese have acquired is only rudimentary fission weapons, and they are still far from nuclear deterrence. The United States is unlikely to be frightened into withdrawing from the war, and of course the Japanese are always wishful thinking and irrational in their decision-making.

On the same day that 419 made the decision to head north to the East China Sea. After the refit, the I-54 submarine, carrying a nuclear bomb, left Rabaul for Marshall. It will make one last resupply there and then head to the target area for this one-way suicide mission. Since the I-12 was still in the vicinity of San Diego at the moment, reconnoitring and testing the anti-submarine measures of the port, Onishi made some revisions when formulating the plan.

In the new plan, San Diego is no longer the only target area, but only the first priority. The plan was no longer confined to the destruction of the enemy fleet, but the choice of targets was given to the commander of the I-54, who decided to choose the most likely target among the three alternative cities.