Well, there were plenty of close calls. If Gojong wasn't as careful in playing the Japanese, Russians and Chinese against each other, any one of them could have absorbed Korea. Japan, in particular, is particularly sticky, considering the growing power of the pro-annexation Imperial Japanese Army. There were even plans to assassinate Queen Myeongseong (who was the architect of Gojong's foreign policy) by the Japanese ambassador, Goro Miura, by sending Japanese ronin into her palace with the help of the Japanese-trained Hullyeondae on site. However, that ended up being called off when she had Gojong replace them with the Russian-trained Hyeondae Gibyeong (otherwise known as the Korean Cossacks, or 'Modern Cavalry'). The backlash was pretty bad, considering her detractors saw a witch consorting with European devils rather than fellow Asians. But let's face it... The Japanese were too absorbed by the belief in European imperialism as a means to gain respect from the Westerners. Korea would have been done for under them.
OOC: And yes, I just realized that Hyeondae Gibyeong could have meant Hyundai Cavalry, which sounds like the K-drama plot for a time-travelling group of Korean mercenaries in Hyundai vehicles. :V