On top of that, the Joseon authorities adopted a rigorous isolationist plan, earning the nickname "the hermit kingdom", but in the end unsuccessful to protect by itself from imperialism and was forced to open its borders, starting an period top into Japanese imperial rule.

Even so the Sui army was lured right into a lure from the famed Koguryŏ commander Ŭlchi Mundŏk, and experienced a calamitous defeat with the Salsu (Ch'ŏngch'ŏn) River. It is said that only two,seven hundred of the three hundred,000 Sui soldiers who experienced crossed the Yalu survived to discover their way again, along with the Sui emperor now lifted the siege of Liao-tung Fortress and withdrew his forces to China correct. Yang Ti ongoing to ship his armies against Koguryŏ 토토 but yet again without having achievements, and ahead of lengthy his war-weakened empire crumbled." ^