Bradley Manning is guilty. He broke the law. In fact, he took a deliberate decision to break the US Uniform Code of Military Justice, and US Federal Law, in releasing classified information to Wikileaks.
This fact has nothing at all to do with whether you consider him a brave and principled whistle blower, being persecuted by a military embarrassed by the exposure of their misdeeds, or an evil pinko terrorist-loving pervert who has disgraced his uniform.
Morality and the law are not the same thing. Whether they should be, or not, is a thorny philosophical issue most easily addressed by the rhetorical question "Whose morality do you pick?"