Sakhalin Island, also known as Sakhalin, was owned by China in the early days, and the Japanese government sent troops to occupy the island during the Toyotomi Hideyoshi period, and in 1644, when the Edo shogunate drew up a map of the country, it was included in the Japanese territory, and in 1689, the Sino-Russian Treaty of Nebuchu stipulated that the island was Chinese territory, but because the Qing Dynasty government did not formally garrison troops on the island, Russia sent an expedition to kill the indigenous people at the northern end of Upper Sakhalin Island at the beginning of the 1st century, and built camps and mined coal mines, and then occupied the southern part of the island at the end of the 1st period.

During the same period, Japan also set up a market in the south of the island, and there were many clashes between the Japanese, Russian and civilians, and the two countries negotiated the partition of Sakhalin Island. In 1860, the Sino-Russian Treaty of Beijing was signed, and this island, which is equivalent to the size of two Taiwan islands, officially belonged to Tsarist Russia in terms of sovereignty, and then Tsarist Russia signed the "Sakhalin Thousand Islands Exchange Treaty" with Japan, using 18 islands in the Kuril Islands to exchange the southern area of Sakhalin Island occupied by Japan, and Sakhalin Island was occupied by Tsarist Russia from then on.

In 1905, Tsarist Russia lost the war against Japan and was forced to cede the southern part of Sakhalin to Japan, but it was reclaimed during the reign of Diana I. As part of the 1928 German-Russian peace treaty, the island fell into German hands several times.

At the beginning of August 1928, the first German marines landed on Sakhalin Island, and then began to hand over the defense with the Russian garrison, and the Russian residents and troops on the island were evacuated with the help of the German Navy, and by the beginning of October, the Russian soldiers and civilians had completely evacuated the island, and the number of German officers and soldiers on the island had increased to more than 17,000, and an ominous number of indigenous people who lived by fishing and hunting.

As early as mid-August, the German army dispatched special engineering troops from Qingdao to Sakhalin Island, and selected four areas in the central and southern parts of the country with relatively ideal terrain and terrain to build large military airfields.

Although Germany and Japan soon began negotiations for land, a large number of German fighters were stationed at the island's airfields, some of them flying directly from the Qingdao base, and others were transported directly from the German mainland by ship. In addition, 61 additional anti-aircraft artillery batteries and a batch of radar equipment from the German mainland arrived by October. A tight network of anti-aircraft firepower was deployed at various airports and ports, and according to the description of the Japanese spy department, "1 the German army is making every effort to occupy the island permanently, and has no intention of exchanging it for land along the coast of the Bay of Bengal."

After the "Nagoya Massacre," the Japanese military once regarded this as a sign that the two countries were about to turn hostile because the German Government urgently announced the termination of negotiations and the recall of all diplomatic personnel stationed in Japan. Therefore, the previously formulated "Iron Cavalry Battle Plan" was put back on the agenda. This plan is quite similar to the Battle of Arthur in the Russo-Japanese War at the end of 1904, that is, taking advantage of the fact that Vladivostok and Sakhalin are far from the German mainland, the army and navy will quickly seize these two strategic points by means of a surprise attack by the army and navy.

In mid-October, the base camp of the Japanese army, which was established as a result of the invasion of Oceania and the war of aggression against China, revised the "Iron Cavalry Operation Plan" on the basis of the latest intelligence, and with the personal participation of Supreme Commander Emperor Showa and Prince Kanin Miyazaihito, Chief of the General Staff, the new plan was to invest in the main force of the combined fleet, including the three aircraft carriers "Soryu", "Shozuru", and "Zuizuru", as well as 8,000 marines. And after the start of the war, at least 52 submarines were put into use to blockade the Yellow Sea and the Sea of Japan. According to this plan, the Japanese Army, which had absolute numerical superiority, would attack Vladivostok from Korea and northeastern China. The task of the Marines and the Native Army was to land on Sakhalin with the assistance of the Navy.

At a time when there is a debate within the Japanese government and the military over whether and when to carry out the "Iron Cavalry". Two very important circumstances brought the controversy to the back burner once again: Germany agreed to reopen the previously suspended negotiations on the condition that the Japanese government would punish the murderers and negligent gendarmerie officials. and compensation for the dead and injured in a total of 10 million yen, both of which are within the limits of the Japanese government's acceptable conditions; Second, the Kwantung Army quickly occupied most of the three northeastern provinces of China in a short period of one month, and the Northeast Chinese Army retreated into the Guannai without resistance, and the German government surprisingly did not intervene, and the Japanese government, overjoyed, thought that this was a signal that the Germans were ready to abandon the Far East, so it shifted its main attention to negotiations with Germany and the consolidation of northeast China, and the army and navy units that had been prepared to assemble soon returned to their respective stations.

Diplomats were buying as much time as possible at the negotiating table, the German Far East Dispatch Force and the Pacific Fleet were also in full swing to make final preparations, and a very important event was the Kaiser's personal order. Air forces stationed in Vladivostok and Sakhalin began reconnaissance on 20 November on important Japanese military targets on the mainland.

The first reconnaissance mission was carried out by three Dornell III ultra-long-range bombers equipped with aviation radars, reconnaissance cameras, and radio listening equipment, for which the General Headquarters of the German Far East Dispatch Army also specially selected three groups of the most experienced crews, and the three captains all participated in the bombing of the United States in the German-American War in 1924 and the bombing operation against Vladivostok a few months ago, and the total number of wartime attendances exceeded 125 times, which was already a very high record in the German air force.

From the selection of crew members to careful planning and preparation, the scheduled date was not long in coming, and good news came from German meteorological experts who have long been engaged in meteorological data collection in Japan as diplomats, and the last two days have been fine and sunny in most parts of Japan. Although it was already early winter at this time, visibility was expected to be quite good.

At 4 o'clock in the morning, at the end of the main runway of the No. 3 military airfield in south-central Sakhalin, the three-bladed propellers of the two super bombers began to rotate one after another, accompanied by the muffled sound of engines and puffs of smoke in Kurakula. Since this was a high-altitude reconnaissance mission, and the distance from here to Tokyo was less than 1,000 kilometers, the three bombers did not need to carry bombs or excess fuel, but only installed three Laika 27 aerial cameras specially used for high-altitude reconnaissance in the bomb bay, and the wireless telegraph room was also simply modified, and a radio listening equipment was installed and a special radio listener was equipped, bringing the total number of crew members to 12. Namely, the co-pilot, the navigator, the bombardier and forward-firing machine gunner, the mechanic and the turret operator, the radio telegraph operator and ambulance, the radar operator, 4 machine gunners and 1 additional radio listener.

At 4:05 a.m., the 171-022 Dornell III bomber was the first to fly off the ground, and it was heading for reconnaissance over Honshu, and three minutes later, the 171-051 bomber also took off, aiming for Shikoku farther away; Almost at the same time, the Dornier III with the designation 166-019 took off from the military airfield No. 2 in Vladivostok and was aimed at the Japanese island of Kyushu.

10 minutes later. Three bombers have disappeared one after another on the monitoring screen of their own warning radars, these new land-based radars are deployed in Vladivostok and Sakhalin Island at the commanding heights and near the coast, under normal circumstances can monitor 40 kilometers away aircraft and 10 kilometers away ships, wartime will provide their own fighters with valuable early warning time, so Germany has deployed special monitoring forces in three bases in the Far East, of which seven "Prophet II" radars and five early "Prophet I" radars are deployed along the coast of Jiaozhou Bay. There are 5 Prophet II deployed at the Vladivostok base and 11 Prophet II at Sakhalin.

At 4:45 local time, the three bombers finally "got out of the monitoring range" of their own air early warning, in fact, the current early warning aircraft of the Luftwaffe are not special early warning aircraft. Instead, airships equipped with airborne radar or Dornier II and III bombers were used to keep watch near the base. The alert airship stayed in the air for a long time, but it was greatly affected by the weather, and the Dornier bomber could stay in the air for up to 20 hours during the alert flight. And it can advance the base warning distance by about 150-200 kilometers.

At 5 o'clock sharp, bombers 171-022 and 171-051 flew over Sapporo, the capital of Hokkaido, Japan, in a two-plane formation, and the instruments on the planes showed that the two planes were flying at an altitude of 10,000 meters at a speed of 450 kilometers per hour, an altitude that the Japanese could only reach with the shells of their own 5-inch anti-aircraft guns. After analyzing the captured Japanese-made fighters and their engines on the German-Russian battlefield, the Germans clearly knew the extent of the Japanese supercharged engines, as experts predicted, at this time no Japanese fighter could fly to an altitude of more than 8,500 meters. To break through this limitation, engine technology is the primary factor.

On the two bombers, the radar operators stared intently at the screens of the onboard radars, and as soon as a Japanese fighter within 30 kilometers took off, their radars could detect it, and the bombardier also watched his sights closely, perhaps he could not hear the air defense sirens on the ground, but the beam of the searchlight could not escape his eyes in any way. However, in half an hour flying over Hokkaido. It was always pitch black on the ground, and not a single fighter plane had risen into the air, and the Japanese "North Gate Key" was unexpectedly open in the air.

If Hokkaido is relatively remote and primitive among the Japanese islands, then Honshu Island, the narrow "original land of Japan", is truly the center of prosperity, which is not only the political center of Japan, but also the core area of Japan's economy and industry, where 90% of the gross national economic output is concentrated, and Tokyo Bay, Osaka Bay and the Seto Inland Sea area are all important industrial areas.

Needless to say, Tokyo is home to the Imperial Family, the government, and the Army, and the Yokosuka Naval Base on the coast of Tokyo Bay is one of the main home ports of the Japanese Combined Fleet and the base camp of the Japanese Navy.

At 5:30 a.m. Tokyo time, nearly one and a half hours before sunrise, it was the darkest time of the day, with a very slight roar, the German bomber 171-022 quietly flew over Tokyo, the altitude was still about 10,000 meters, at this time Tokyo was sleeping, the ground was silent, and the German plane could not shoot in the air in the dark, so it just circled nearby. Eventually, the soldiers guarding the Imperial Palace heard a strange noise from the air and reported the situation to their superiors, and the Japanese became alert. At 5:42, the Tokyo Garrison Command ordered the searchlights to be turned on, but the three searchlights used by the Japanese army - 90 cm, 110 cm and 150 cm searchlights only had a range of 4,000 meters, 6,000 meters and 8,000 meters, and it was impossible to observe the German bombers at an altitude of 10,000 meters with the naked eye, and the air defense listeners could not locate the planes at such a distance. According to the results of the monitoring by the radio monitors, the Japanese side did not use radio detection equipment during the entire process.

At 5:47 a.m., 171-022's on-board radar spotted four Japanese fighters rising from the western suburbs of Tokyo, but the other side was unable to fly to the altitude of the Dornier III bomber as expected.

At 5:50 a.m., 171-022 left Tokyo and headed south, and by the time it reached the skies over Yokosuka Naval Port, it was just dawn and airborne radar detected the movement of a large number of ships moored in the port, and a large number of Japanese fighters took to the air to intercept them, but they still failed to pose a substantial threat to the high-flying German bombers. With limited light, 171-022 managed to take a set of images of the Yokosuka Naval Port, then turned around and flew back over Tokyo, where another set of photos were taken, at which point the Japanese on the ground were finally able to see the gray plane through binoculars. - At 6:43 a.m., it was already dawn, and 171-022 flew southwest under the watchful eyes of a large group of Japanese fighters, while the two bombers bound for Shikoku and bound for Kyushu did not receive such good "treatment"

They photographed more than a dozen Japanese cities and military bases, but the Japanese on the ground seemed quite calm during the whole process, and it was only at about 7 o'clock in the morning that the Japanese suddenly went crazy and sent a large number of fighters into the air, but the two German planes soon left satisfied.

On the morning of the same day, the Japanese Foreign Ministry lodged a serious protest with the German Government, but the German side explained that the three German bombers had "lost" while flying between Qingdao and Sakhalin Island, and therefore strayed into Japanese airspace. (Full Text)