Would you call Bradley Manning a hero or traitor?

Bradley Manning hero or traitor? Now many will see him as a traitor because he leaked secrets that embarrassed the US. Others see him as a hero that exposed cover ups and war crimes that might have never seen the light of day and continued to be done in a pertinacious manner (even though it may still be going on just hidden better) He did take an oath to defend this nations against any threat both foreign or domestic. If he thought the government was doing unethical things should he be loyal to the government and not challenged it, or exercise his right of the constitution to challenge the government and even bring it down if it starts to get to big and powerful for its own good? What other way could he have used to expose the cover ups of the government?