"Your Majesty! Your Majesty! We have received information from merchants traveling between Japan and Silla!"
"What news is that?"
"They say the Wa are constructing a thousand warships and preparing to sail for Silla. The target is presumed to be Seorabeol in Silla!"
"Damn it! What kind of nonsense is this?"
The event he had feared had actually occurred. Dae In-seon had anticipated it, but the timing was far too soon.
By the time Gaegyeong's repairs were completed, Later Baekje had sent an envoy to Japan, discussing its historic ties with Baekje. They promised that if Silla were subdued and Goryeo pushed back to the Amnok River, Silla's land would be ceded to Japan. This plan gained the support of Fujiwara no Tokihira and Sugawara no Michizane, and Emperor Daigo agreed with their proposal to aid Baekje once more after the Baekgang River campaign.
After Later Baekje's envoys met Emperor Daigo, the Left Minister Fujiwara no Tokihira, the Right Minister Sugawara no Michizane, and the Emperor began secret discussions on the invasion of Silla.
Initially, Emperor Daigo had no particular goodwill toward Later Baekje. The sudden suggestion to cooperate to subdue Silla in exchange for territory seemed like a superficial pretense, and he had only intended to appear to consider it.
Seeing Daigo's ambiguous attitude, Michizane wanted to argue against going to war, but Tokihira pressed strongly in favor of aiding Later Baekje, leaving him little room to oppose.
"But is this truly wise? Goryeo is the other party. Helping Baekje would make us enemies of Goryeo, would it not?"
"How weak your words sound! Crushing insolent Silla is an excellent opportunity to extend our influence to the continent."
"…Hmm. Still, turning against Goryeo feels… questionable."
Daigo had little real knowledge of Goryeo. He knew only that Goryeo furs were popular in Japan, and that past envoys described Goryeo as underdeveloped. He had also heard that the current Goryeo king was strong and resolute, making hostility toward Goryeo somewhat uncomfortable.
But with Tokihira persistently advocating the Silla campaign, the decision was gradually leaning that way.
"Your Majesty must not falter. Goryeo once arrogantly claimed to be a 'son-in-law nation' and insulted Your Majesty, the most noble Emperor under heaven. They dare call themselves descendants of the heavenly lineage! They must be punished. Silla, too, deserves retribution. They continually raid us whenever possible—how could we let them remain unchecked?"
"And the Right Minister's opinion?"
Tokihira's argument seemed to carry weight, so Daigo asked Michizane for his view.
Even with the question posed, Michizane hesitated to form a conclusion.
In fact, the invasion of Silla was not entirely impossible. And if allied with Baekje, they might deal a blow to Goryeo, which shared a border with the Chinese mainland.
Still, this was only a possibility. Michizane did not believe success was likely, so he opposed direct intervention. Yet abstaining while Baekje conquered Silla would give Tokihira the perfect excuse to criticize him.
'Better to step back cautiously. If they fail, it'll give reason to bring down Tokihira. We'll see.'
Eventually, Michizane decided to hold back.
"…I simply follow Your Majesty's decision."
Upon hearing this, Tokihira clicked his tongue, inwardly disappointed.
But he soon conveyed the consensus to Emperor Daigo:
"Since the Right Minister concurs, Your Majesty should ally with Baekje to strike Silla and secure a foothold on the continent."
"Very well. Act according to the Left Minister's advice."
Daigo nodded in approval.
The moment news of Japan's planned attack on Silla reached Gaegyeong, the city immediately went into wartime mode. Dae Wi-hae, who had been repairing Gaegyeong to serve as a temporary capital, rushed to find a stressed Dae In-seon, who was clutching his head.
"Shall we withdraw the Liaodong army?"
"No, Liaodong is not an option. How about the Second Army, Sixth Division? Over 30,000 strong."
Half-dazed, Dae In-seon reverted to the respectful nephew, appealing for his uncle's assistance.
The Second Army, Sixth Division, modeled after Qing's Eight Banners and Goryeo's historical military structure, numbered over 40,000. Yet at this time, they were mainly policing the growing population of Sanggyong and defending the Five Capitals.
"And Sanggyong's defense?"
"Relying on nobles' private guards is insufficient."
"Would the Han Army Eight Banners be enough?"
"They consist mostly of Han recruits, trained lightly. With a thousand enemy ships, it would be difficult to stop them."
The Eight Banners were primarily a Han force created to provide employment to Han settlers. Though partially trained, they were far from elite.
"Can we handle it at sea?"
"The new warships are not yet completed, and most of our navy is stationed at the Amnok River mouth and Jangsan Islands. Gathering a few hundred ships will take time. Even if we intercept them at sea, our fleet, returning from a long journey, might not hold. Besides, we must consider clashes with Baekje's navy."
"How many troops would a thousand Wa ships carry?"
"The ships are small, so unclear. But at least 20,000 troops could land."
Historically, Japanese ships during the Heian period were primitive. Even a thousand ships could not carry huge numbers. Yet even with poor-quality ships, landing forces would easily overwhelm Silla.
"…Silla cannot possibly hold them."
"Even if Silla resists, if Baekje strikes alongside, there is no hope."
"Ha, these Japanese are trouble wherever they go. A thousand ships? That's the scale of the Baekgang campaign."
Long ago, Japan had sent a thousand ships to aid Baekje. Their vessels were mere modified logs, capable of carrying only limited troops.
Now, however, Japanese shipbuilding had improved, and Goryeo could not leave the declining Silla to fend for itself. Dae In-seon concluded that Goryeo must dispatch substantial forces to minimize Silla's losses.
'The Eight Banners alone are insufficient. Better to draw troops from Pyongyang, Gaegyeong, and surrounding fortresses, leaving minimal garrisons on the Baekje border, and sweep the Wa forces.'
After much deliberation, Dae In-seon finally erupted in frustration.
"Damn it. Japan is no help at all! Be it the 21st century or now, they are utterly useless!"
"Your Majesty, please calm yourself."
"Ha… truly useless. Wait…?"
Initially ready to curse, he paused and realized this Japanese expedition might actually benefit Goryeo.
'Hold on. This isn't all bad. They give us a pretext to subdue Silla. And with this pretext, why not conquer Japan itself? Currently, our artillery can only equip 1,500 men at most, with minimal gunpowder. Saltpeter is obtainable, but sulfur is lacking. Japan, on the other hand, has abundant silver and sulfur. This could be an opportunity.'
Xitu's constant wars had brought wealth from arms trade, but depending on it alone would bankrupt Goryeo eventually.
Population was rapidly increasing, leaving no focus for reforms.
While China remained divided, having a wealthy neighbor like Japan was advantageous. The solution was clear: Japan. Not merely a source of wealth, but a densely packed treasure trove.
"Your Majesty?"
"Uncle, I am famished. Look at this archipelago of the Wa. Does it not look delicious?"
"Your Majesty… you intend to conquer Japan?"
"The name 'Japan' is too generous. Let's call them Wa instead. They are a country soon to disappear."
Dae Wi-hae was unsure how to react.
Goryeo's treasury had already been heavily spent on reforms, road networks across the Five Capitals and central Korea, and the naturalization of refugees. War would demand even more. An expedition to Japan could bring finances to the brink of collapse.
"Considering naval logistics, I fear our finances may not hold, Your Majesty."
Dae In-seon ignored the concern, burning with determination to subdue Japan.
"We'll find the money somehow. There's also plenty of justification. Those damn Wa call their king 'Emperor,' pretending to emulate the Son of Heaven, while we, inheriting Goguryeo, exist. They dare call themselves emperor!"
His drive was partially fueled by the 21st-century Korean anti-Japanese sentiment, but knowledge of Japan's repeated continental ambitions in history also motivated him. Conquering Japan would secure Goryeo's rear.
Above all, Japan was a treasure trove of silver and sulfur.
Dae In-seon was, at heart, a man of ambition.