Although Söngsam and Tokchae in "Cranes" represent opposite sides of the war, they share similarities. Compare their characters and their situations.

In the short story "Cranes," Söngsam and Tokchae are two childhood friends who lost contact throughout the years and find themselves on the opposite sides of a conflict. The latter is a member of a communist agrarian collective whilst the other is an officer. Although they are, politically, on opposing ends, they are very much alike since they grew up together. However, their common or shared experience is the fact that both had to make sacrifices due to the war.
In particular, both Söngsam and Tokchae had to do what was best for their family. As fathers, they each tried to protect their loved ones but in different ways: one stayed whilst the other ran away. Neither action was wrong, but was a decision based on their particular circumstances at the time. They also seem to be well aware that they are both pawns in the larger political games of the war. This perspective and ability to empathize with one another paves the way for Söngsam to allow Tokchae's escape.