"...Operation Z, so named after the famous "Z order" given by Admiral Togo at the Battle of Yaeyama, was not exclusively aimed at Formosa and the Pescadores, even if the Mako Harbor attack is the most well-known episode of the events of September 14. Indeed, what makes Japan's planned coup de main against the French on that day so impressive was that it was executed across a variety of theaters, all within hours of each other, and that French spies and codebreakers had not detected anything amiss that suggested it might be in the offing.
Indeed, the first engagement was not on the 14th itself but, rather, shortly before midnight, when Japanese vessels originating at Kure Naval Base surreptitiously moved from where they had been moored just east of Tsushima Island through the Manzeki-Seto canal into the West Channel of the Korea Strait, where they steamed towards Busan and cut underwater telegraph cables near the harbor's approaches, managing by some miracle to avoid detection by the USS Hunter, a destroyer on a routine movement towards nearby Port Hamilton. Four hundred Japanese marines, or rikusentai, came ashore around three in the morning six kilometers east of the city and moved quickly through the hilly terrain adjacent to the city, and at dawn the cannon fire of the small squadron of Japanese destroyers docked off the shore of Pusan opened fire. The rikusentai, with Korean translators in tow, quickly moved on the town as French soldiers scrambled out of bed, stunned by the attack, and shouted as loud as they could to Korean mercenaries guarding the town that they would not shoot anybody who laid down their weapons and that the French "occupation" of Busan was, officially, at an end. The Battle of Busan took no more than three hours, and was over before ten o' clock. Twenty-seven Frenchmen and Foreign Legionnaires died, along with roughly forty civilians; only two Japanese lost their lives, and sixty-two Korean mercenaries were killed. The French who surrendered were taken to Japan, where they would be imprisoned for the remainder of the conflict in comfortable conditions near Kure. [1]
The Japanese seizure of Busan would kickstart Japan's participation in the war for primacy in the Orient between France and Germany, but also badly scramble the internal dynamics of Korean politics. For those with long memories, it reminded of the Japanese interventions in Korean affairs in the 1880s, which the Gojong military reforms and coziness with both the United States and Russia had been intended to foreclose upon in the future. It also meant that two of Korea's key ports, first Wonsan and now Busan, were in the hands of Japan, which raised alarms as much in St. Petersburg and Philadelphia due to their economic and political interests in the Korean Peninsula as it did in Paris and London; if Busan were to become a Japanese concession long term, it would allow them to close the Korean Strait at will.
It also proved a contentious point at a time that Gojong's health was beginning to fade; this bold provocation by Japan left open the question of how the various personalities of Young Korea would handle an ascendant Japan at a time when the sovereign going back close to forty years was near death..." [2]
- Land of the Morning Calm: Korea's 20th Century
"...the flagship Bretagne, a relatively new dreadnought deployed to serve as the lead vessel of the Far East Fleet. Joining her in what was then known as Makeng Harbor on the namesake island were two pre-dreadnought battleships in Patrie and Gaulois, as well as the cruisers Jeanne d'Arc and Champagne and an escort of four destroyers, seven torpedo boats and eight defensive submarines. As a quirk of history, Francois Darlan - the French State's future strongman - was an officer aboard the Gaulois, and his daring on that day and many to come helped build the legend around him that would eventually form the core of his cult of personality.
The first wave of Japanese planes launched from Pingtan shortly before dawn; with an effective range of a little over four hundred and fifty kilometers, they were expected to strike their target and, rather than turn around and head back, instead head west to Amoy, which sat under blockade of submarines and destroyers and which the Northern Squadron of the Far East Fleet was assisting in a "distant" blockade to which they could respond to threats against in less than three hours out of Makeng, an effective fleet-in-being. Several of the planes, due to the darkness and fault compass equipment, accidentally flew too far east or west, with several missing the Pescadores entirely before turning around to Amoy in a panic and others flying over Formosa instead, with some pilots landing in rice paddies on the island rather than risk running out of fuel over the Straits. The development of air-launched torpedoes in 1919 was primitive, with the most successful experimental variants having been built by the Italians and French (with the other country's navy in mind as a likely target), and Japan lacked the same scientific base and military design bureaus as the more advanced Western navies. Nonetheless, the prototype torpedoes dropped from the Japanese planes would do some damage to the French vessels, and the real target was bombing shore facilities in preparation for harassing an attempted sortie out of the harbor.
Admiral Maurice Grasset, commander of the whole Far East Fleet, gave out the call to general quarters just as many ships were completing their Sunday Mass atop decks. The first wave of planes roared overhead, scattering bombs across the docks, barracks and depots lining the southern and eastern shores of Makeng Harbor, with many of the bombs hitting their targets and one in particular setting up a gunpowder magazine that made the entire harbor shake and even damaged the Patrie. The cannons on several ships roared to life, taking out a few of the Japanese planes, but most of the intact squadron was able to make it out after their run, even if they had done less damage than planned, and veered off towards the mainland.
This course initially persuaded Grasset and his commanders as the boilers roared to life and the Bretagne slid out of its anchorage that the bombers, which were largely unmarked, were German, and had launched from Amoy as part of a sneak attack ahead of fleet action to break the blockade; for a moment, Grasset pondered whether a German squadron had perhaps passed through the Nicaragua Canal or around Cape Horn, steamed across the Pacific with a stopover in Samoa or the Solomons to refuel and regroup, and then found some way to evade French patrols near Mindanao and the Sulus to slip around the southern coast of Formosa. As the Bretagne and her escorts passed out into the central sound of the Pescadores, however, this thought was quickly dashed as vessels appeared over the western horizon, visible around the promontory of the Fisher Island Lighthouse - the 2nd Fleet, heavy on cruisers and destroyers, attempting to block the French in from the southwest.
The problem for Grasset, at this point, was that the battleship-component 1st Fleet was to the Pescadores' north, blocking his potential escape, and both fleets in positioning themselves as such had effectively crossed the T and formed a cauldron around the north, west, and south of the horseshoe-shaped island chain [3], leaving only a narrow passage out to the east past Chuton Island. Grasset, desperate, ordered two destroyers to head out via the Chuton passage and potentially clear an opening if necessary, only to moments later receive their distress signal as Japanese submarines lying in wait struck them with torpedoes. The 1st and 2nd Fleets then began their probing salvos, testing the distance between their positions outside of the islands only eight to ten kilometers away. [4][5]
The second bomber squadron arrived at this point, now in the full light of morning, and there were no waylaid planes this time. Most bombs landed in the water, but one struck home on the damaged Patrie and detonated the whole ship, killing hundreds of French sailors. As this bomber wave cruised through, Grasset made the decision that his ships would simply have to fight their way out to the south, avoiding the battleships to their north and if they had to would blast a path through what he considered inferior (and now clearly Japanese) vessels. He signaled to Formosa his plans and pressed forward into the gauntlet.
The Northern Squadron of the Marine Imperiale's Far East Fleet made a gallant show on September 14, 1919. They had been caught in a brilliantly devised attempted coup de main that combined Japan's efforts at both Manila Bay and Yaeyama from the 1903-04 Spanish-Japanese War and also now included aerial bombardment from above; the attack had been sprung early on a Sunday morning when most of the sailors and officers had been asleep or in Mass. It happened at a French naval outpost isolated in the middle of the Formosa Strait and on the other side of the world from the Metropole and over a thousand kilometers from the Far East Fleet's other major base at Cam Ranh. The Japanese enjoyed air superiority (the rudimentary airfield on Makeng had been the first obvious target of the bombers), the element of complete surprise, and considerably more firepower, especially after the annihilation of the Patrie. But the French fought on, even as the Bretagne suffered several direct hits and began to take on water and eventually had to be abandoned off the coast of Swatow, where Grasset and the majority of the crew were able to escape and come ashore. The Jeanne d'Arc took on water and flames closer to the Pescadores, burning into the early afternoon like a beacon on the deep blue waters of the Orient, but her crew still fired volley after volley even as the fires crept close to the their magazine and finally detonated the vessel like a great brazier with all hands. Champagne and Gaulois, despite losing the vast majority of their destroyer escorts, were able to blast their way through and steamed immediately southwards as fast as possible towards Hong Kong, where they would harbor for two nights before redeploying to Hainan, heavily damaged but seaworthy. The three capital ships lost by the French, along with the losses of almost all destroyers and defensive torpedo boats, was the worst loss by the French Navy since Trafalgar, but the bravery exhibited in breaking through the Japanese gauntlet would earn them a place in the hearts of their countrymen forever from then on.
Of course, the Japanese were not going to complain. Despite losing several cruisers and pre-dreadnought battleships, they had achieved their chief strategic goal, which was the elimination of the French presence in the Formosa Strait and gave them total command of the waters between Pingtan and the Pescadores. With that coup de main, the blockade of Amoy was effectively broken - the French vessels off the coast of Fukien immediately evacuated southwards or to Takau upon hearing that Makeng Harbor had fallen - and vessels could now resupply German positions there. It also meant that Formosa was, quite critically, suddenly isolated on her own, supine to any future Japanese attacks, unless the French committed a great deal of resources to her rescue, and quickly..."
- The French Orient
"...with their declaration of war in hand.
The speed at which Japan enforced their will was what shocked French policymakers. The very next day - Monday, September 15 - Japanese soldiers came ashore at Liukung Island, site of the main coastal battery of the Austro-Hungarian Empire's concession at Weihaiwei, and seized it with barely a shot fired, rapidly overruning the small Austrian garrison there after sinking the two coastal defense ships in harbor from nearly ten kilometers away. By the following weekend, another surprise had been sprung - a detachment of Japanese troops that had left Tsingtao and rapidly moved across the Shandong hinterland before attacking Chefou from the south, thus evading the makeshift defenses French forces had established in the high hills immediately to the city's west in anticipation of an expedition from Chinese forces. Chefou would hold out for a week despite aggressive attacks from remarkably capable Japanese infantrymen as well as bombardment from the sea, but it too eventually fell. The outposts of the French Orient were falling, one by one.
The reaction in Europe was one of panic. The Austrians had depended on the French security umbrella provided by the triangle of Busan, the Pescadores, and Chefou to maintain their sole overseas possession in Shandong and were despondent; those feelings were multiplied by many factors in Paris. Raymond Poincare, the right-wing and highly nationalistic Prime Minister, angrily denounced the Japanese surprise attack upon Makeng as a "day of infamy" and promised "we shall make the oceans run red with the blood of the Japans" and further suggested, "La Patrie shall not rest until we have ended for good this yellow menace that blights the world." Protests erupted across Europe against Japan, even in neutral countries; the previously Germanophile Spaniards, themselves having suffered a similar humiliation at Japan's hands sixteen years earlier, suddenly expressed sympathy for France and several of their retired admirals traveled over the heavily-fortified border of the Pyrenees to offer their services as advisors to the French Admiralty in dealing with the "savage" Japanese. Even in the United States, about as far from the violence of East Asia as was possible, anti-Japanese riots occurred in cities on it West Coast, with fears of Japanese intervention against possessions like Port Hamilton or Chusan now live.
The war had only really begun now with Japan's audacious attack, but it was already a new, strange kind of war, termed in civilizational struggles, and more of a coming-out party for Japan than even her skirmish with Spain had been. Whatever happened after, Asia could not and would not ever be the same..."
- Steel Typhoon: The Oriental Theater of the Central European War
[1] The Japanese in WW1 treated their prisoners of war as well as any other power did; the whole "compete over who can be as barbaric towards POWs as possible" energy of the Japanese military was very much a WW2 phenomenon.
[2] So me being dumb forgot to cover Gojong's OTL death in January 1919. Chalk it up in-universe to him living a less-stressful life without the Japanese occupation and his frequent imprisonment, but let's also ignore the rumors that he was poisoned by the Japanese and assume he really was going to die sometime around the late 1910s/early 1920s
[3] I hope you're all referring to a map for this update in particular, but it's funny that the Pescadores/Penghus look kind of like the alien script from "Arrival" (one of my all-time favorite films)
[4] Deck guns on a dreadnoughts typically had a range of 25,000 meters or twenty-five kilometers, much better than land artillery
[5] Is this a similar trap to Hilton Head? Yes, yes it is. That wasn't my initial plan until I started really looking at a map of the Pescadores. Also, I'm allowed to plagiarize myself, so.