Personal opinion of members of the history club - Continental Baekje is a clear theory.

 Looking at the Samguk Sagi and other books, it seems that Silla has a significant difference in national power from Goguryeo Baekje among the three countries. There was a time when the capital was violated by the Baekje army, and in terms of sending envoys to Goguryeo to hit Japanese pirates, Baekje, Goguryeo, and Silla did not seem to have thought that they were very threatening at that time. On the other hand, Silla seems to be a country that is quite good at diplomatic power. How should I say this? It seems that Baekje maintained its country in this way, sticking to Goguryeo when it becomes stronger and Baekje when Goguryeo becomes stronger. And the decisive reason for acknowledging the Baekje theory of the Sohae continent is that when King Jangsu took power after King Gwanggaeto the Great, King Jangsu made unification of the Korean Peninsula more important than the northern territory. Like his name, he was in power for a very long time.  At the time of Goguryeo, a tremendous country, both in terms of territory and national power, focused on unifying the Korean Peninsula for decades. In order for the story to be established that Baekje could not be completely pushed out, I don't think it makes sense as a territory of Baekje that we saw in the national history book. If it's a short-term match, I don't know... If it's a long-term war, in a war atmosphere that's been going on for decades... I think it's almost impossible to endure that much territory. If you look at the national history books we read at that time, you can remember that the territory of Silla + Baekje was less than 10/1 of the entire territory of Goguryeo. I don't think it's possible to call it the Silla Baekje Alliance.   At that time, Goguryeo was at its peak, but it was not able to beat Baekje even after focusing on the Korean Peninsula with a tremendous amount of national power on the continent of China to destroy the Yeon Dynasty.  I don't think it makes sense.  Although the information about Baekje we know is ridiculously small compared to Goguryeo, Baekje was the country that won and lost the war against Goguryeo at that time.   And as you all know after reading "The Three Kingdoms"... Even if you look at Gong Myeong Hae-ja's world triad, if one country does not have enough national power to beat the other two countries, the three countries will be maintained. Just looking at the fact that Baekje existed on the Korean Peninsula for hundreds of years as a rival to Goguryeo's territory, national power through war performance against other peoples, and the horse race reigned as a powerhouse in Northeast Asia on the hundreds of years, I can guess Baekje's national power. Even if I think that the theory of the Three Kingdoms on the continent makes little sense, I think Baekje's national power was comparable to Goguryeo at that time. Looking at the contents covered by the History Special during the fall of Baekje. In the case of Japan, the Japanese king directly commanded large-scale troops to support Baekje. Looking at the letters and historical records of the Japanese king at that time, it is thought that Japan, a great country called Baekje, is a satellite country until the fall of Baekje.   And the fact that it had territory in southern China is somewhat acceptable. In terms of Baekje's territory at that time, Japan, the Korean Peninsula, and southern China. I think they're like islands in southern China.  I think this much territory is comparable to Goguryeo's national power through Baekje's maritime trade. And I think the source of Silla's unification of the three kingdoms was excellent diplomatic skills.