Did KIM JONG IL do the right thing to let two journalists go?

Yes he did but was astute enough to gain political leverage from the situation. Surely, after investigation Jong knew that the women were hardly a real threat to national security - they weren't pro spies, were easily caught at the border and never got to see anything compromising.

However, he had to exact some punishment to satisfy his hard-line supporters and also send a message of deterrence. It's noted that despite their sentence of 12yrs of hard labor in prison, Kim never sent them to actually serve the draconian sentence. He knew that he had to let the young women go, especially so when one of them has a young child. It was just a matter of getting what he wanted in exchange for their release.

If this particular situation was reversed, the US would detain them for debriefing, then deport them.

We deport undocumented aliens. At our cost.

YES.

As stated America wouldn't do much to them!!