This is the second-highest classification. Information is classified Secret when its release would cause "serious damage" to national security. Most information that is classified is held at the secret sensitivity.
Classified information in the United States - Wikipedia, the free encyclopedia
NOFORN means No Foreigners, this primarily exist because some service members are not US Citizens and because some information is shared with allies and some is not.
I am not for sure in what light you posted, but it kinda of sound like, gee, it's only Secret NOFORN and Top Secret, so hey, it's ok. I hope that is not the way you look at it, but if you do, I guess you are entitled to that opinion.
Interesting that they are only charging with Aiding the Enemy, Article III Section 3 of the Constitution states, Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies, giving them Aid and Comfort. No Person shall be convicted of Treason unless on the Testimony of two Witnesses to the same overt Act, or on Confession in open Court.
So, the way I read that is, Aiding the Enemy is definable as a treasonous act.
The UCMJ defines Aiding the Enemy in Article 104
ART. 104. AIDING THE ENEMY
Any person who--
(1) aids, or attempts to aid, the enemy with arms, ammunition, supplies, money, or other things; or
(2) without proper authority, knowingly harbors or [protects or gives intelligence to or communicates or corresponds with or holds any intercourse with the enemy, either directly or indirectly;
shall suffer death or such other punishment as a court-martial or military commission may direct.
If he did leak secret information to Wiki Leaks, then his action would indeed fall under Article 104 Paragraph 2. Also, if the military were to conduct His Courts Martial in accordance with this article, he would face the Death Penalty, not just life in prison.
I don't know exactly what information he leaked, but if I was sitting on the panel (military jury) and he released any information that could help either insurgents in Iraq or Afghanistan, then I would indeed find him guilty under this article and since he did during a time of armed conflict, I would vote for death.