Transcript for Chelsea Manning says she didn't think her leaks would threaten national security
She's among the most tumultuous public figures of our time. Convicted of passing classified information to WikiLeaks. Chelsea Manning story strikes at a fundamental dilemma of our cyber age. The delicate balance between protecting government secrets. Verses the public's right to know. Her groundbreaking fight for transgender rights and her controversial clemency have thrusts her into the center of so many ideological skirmishes. She sat down with me exclusively for her first ever television in view. And and blending into the crowded streets of New York City. Fifty and I'm assuming you'd never know this young woman. He's one of the most divisive figures of our time. And should not have been turned into a martyr for or. He's a hero. Chelsea Manning the transgender soldier convicted of leaking the biggest trove of government secrets in US history setting off a firestorm of controversy. Sensitive documents whistle blower protections about government secrets. The real potential threat. Security and it. Is right to know at 29 she spent nearly a quarter for life in prison and up until this week has only told her story through words on paper. So many people call you a traitor. Many call you a hero. Who is Chelsea man I'm just me. It's a simple and yet the road to get here has been wrong. Growing up in the Oklahoma Bible Belt she was known then as Bradley Manning she says she found it increasingly difficult to fit in. Really struggling gender at struggling as a teenager. I'm like looking for my place in the world what made you feel the call to enlist in the military. Let's see on the television on the evening news and a surge in Iraq Iraq. Descending into chaos you know I felt like maybe I can do something maybe I can make a difference. Manning's computer students earned her spot as an army intelligence analyst deployed to Iraq where she was tasked with sifting through classified reports but she says it opened her eyes it was starkly different version of the war. Images like d.s American soldiers opening fire from an Apache helicopter. They had right through the windshield. On what would turn out to be civilians including children. Yeah. Among the twelve dead two journalists from Reuters. Everything that you need to know about warfare it's right there in 147 minute that you. Wendy Newman counterinsurgency warfare is not a simple thing there's not there's no it's as simple like good guys vs pack ice in his next. Many says she read news articles about how Reuters had tried in vain to request this video for two years so she decided to bring it up the chain of command pointed. You're she's back it's just another incident do you resent it sticks out as a prominent is because it was two journalists there. Thousands and thousands of yes but. As Manning is dealing with hard drives full of government secrets she's grappling with the secret of her own. In a moment of desperation she emails this photo of herself to a superiors saying this is my problem is the cause of my pain and confusion. It was draining after. You know I felt like I'm not being myself so she sought solace online in Wiki leak themed chat rooms anymore means that be able to safely and securely. Reveal government wrongdoing you decide to risk your career to break the lomb. Won't wasn't that you're seeing that compelled to do them I stopped seeing yes statistics and information and I started seeing people. Writer currently engaged in a talk pleaded individual. So Manning decided to leak and released that air strike video and later other classified documents to WikiLeaks. The material that is. Dramatic. It was classified. Thus began a game of cat and mouse the contacts named Nathaniel who Manning said she believed was Julian Assange himself. At the time WikiLeaks was just an obscure open government web site. So why WikiLeaks then. I think it's a partner Robin context I try to go to you know to the Washington Post first and I try to get in your time. Over the course of four months she leaked diplomatic cables battlefield reports and Guantanamo detainee profiles. More than 700000. Documents in all. The impact explosive. It's the biggest lead the US military history their names for their operations. It is an attack on the international community's less than two months after disclosures first made news Manning would be taken into custody from her barracks in Iraq. Did you think you would ever get caught where you ready to pay the price and not focused on consequences. Or what this means or what that means I'm focused but dated debt meanwhile the government scrambling to assess the actual damage Manning's leaks had Conn missed. Do you consider tell cementing a whistle blower. Re clinch it was a high ranking intelligence official at the NSA at the time. She didn't go through any of the whistle blowing channels and should have she could've gone to the judge after general to their country or congressional representatives. They would have welcome back. So you didn't think any of it was gonna threaten national security now. There are some higher ups in in the intelligence community who would argue. You know you're a low level. Analysts there's no way you could've known right outcome that would have been. Right this is the report is at airports at work when I'm a subject matter expert office and yet. One could argue she was willing to put her own. Liberty and her own military career on the line in order to expose the. This at some extraordinarily arrogant a you. It does to me. In what way. It's to say that my judgment is better than that of everybody else and so I'm going to take this upon myself. To make this decision with consequences I couldn't possibly understand and I'm gonna do it because it makes me feel it from doing the right thing. That's the definition of air. Turns out some of the low level army battlefield reports that Manning leaked were found in Osama bin Laden's compound after his death. You may have been motivated to get that. Information into the public's fear that you might have also given it to our enemies right to have our responsibility. For the public. It's not black and why it's a. It's complicated. But the law. Was clear back in the states the military's response severe. 22 charges many under the Espionage Act she was facing up to a 136. Years in prison. Now in a military brig. Quantico she'd faced nine months of solitary confinement before a report Matsui to begin the military says for her own protection. What we're those days like for you it's a mind game saying you're sitting in around by yourself. The UN investigator called it cruel and and human right. Men and ultimately pled guilty to some charges an after a two month long court martial. The burning. The army private convicted of leaking America's secrets but spared by the judge from the most serious charge aiding America's enemies. The sentence handed down the longest ever for stealing classified information. Here you are 2.5 years olds. When they said 35 years in prison what went through your mind. You're thinking more opt out. How to getting it through the next day. Manning's appeals lawyers Vince ward David Hammond and Nancy Hollander say the military was trying to make an example of her. They overcharged. In the overreacted. And tried to turned to the case of the century and pay her case striking a nerve about the Jerious balance between government accountability we should be prosecuted and protecting our nation's secrets. We've nominating for noble prize I think he's completely at trader I mean you can't be messing round. With national security dad he deserves a medal whistle blowers have a very important part in our government. Within days of. Being sentenced Manning became the poster child for another congress and more controversy. What made you decide to come out as Kansas after being sentenced. Had to be and I asked. But at Fort Leavenworth amends military prison she had to fight for her right to exist as a transgender woman so you're. Despair was not with the 35 year prison sentence it was much more media. It had more to do with you needing to be. Chelsea. I had never done that had never analysts had to be at first the military denied Manning's requests for medical treatment for her gender transition. Won't you say to those who feel that taxpayers shouldn't be paying for hormone treatments. Well you know it's. Health care is something that prisoners. Our right to and trans trance health care is asks are you won't let me instruments health care necessary. Medical care so there live keeps me a lot keeps me from from. From feeling like I'm in the wrong body in. You may you know like diet thanks I get these horrible field a used to get these horrible feeling as when a rip my body part it's really really awful. Help your prayer for transgender people it is not cosmetic is not experimental. But with the help of ACLU civil rights lawyer chased Ngo Manning was eventually granted hormone therapy undergarments and make up. All of this heralded as landmark victories. She was the first person to receive hormone therapy and in military prison. Chelsea needs us now more than ever. I've never stop fighting for Chelsea and I transgender siblings. I want people to see the truth. Manning's falling on the outside growing bolstered by her prolific writing and tweeting about everything ranging from her thoughts on government transparency. To share in favor play lists. While outside Manning supporters were fighting to sway the court of public opinion from behind bars. I think the you can see that Chelsea speed of mind. Was that she was deteriorating. Throughout the the process of the appeal and you grew so just there. That you tracks take. Yes. It's a very dark flakes. Yeah eight years you're you're like if I can't be needs and landmines. You just want the pain stop the pain of not knowing. Who you are or why. You are this way. Is wanted to go away. And then to make matters worse she was sent to solitary confinement that prisons said that she interfered with the good order and discipline of the prison. By attempting to kill herself is just a horrendous. Thought if you think about it. She was punished for trying to survive and that she was punished. For trying to die and that was just an incredibly bleak hard time. That was daring us the summer when he sixteen. So her legal team decided that asking President Obama for mercy for a shorter sentence ruling Chelsea's only home. When we come back and I wrote a letter to Obama and his real animals rock and was only intended for him.
This transcript has been automatically generated and may not be 100% accurate.