In "Cranes," what is the real reason that Songsam unties Tokchae?

You need to analyse the
role of the flashback which we are told about just before the end of the story. In this
flashback, we are persented with the two men as children, and how they together caught a crane,
and then realised that its freedom was worth more than anything. Consider how this release of
the crane is described:

But the next moment, as another
crane from a nearby bush fluttered its wings, the boys' crane stretched its long neck with a
whoop and disappeared into the sky. For a long time the two boys could not take their eyes away
from the blue sky into which their crane had soared.

Clearly the way in which the boys are mesmerised by the blue sky shows the way that
they value freedom more than capture. The decision of Songsam to therefore let his friend escape
and enjoy the same freedom indicates their understanding that freedom is infinitely more
important than capture, and also symbolises how the strength of friendship can overcome the
power of competing ideologies.