By Libby Lewis
Listen to Libby Lewis' report for CNN Radio:
So many questions are swirling around Bradley Manning as the military holds a hearing to present evidence about his alleged crimes. (See the rest of our Bradley Manning coverage here)
Perhaps the biggest question raised about Manning is: How did this troubled young man - and a low-ranking one at that - get to handle such sensitive information with the ease of a kid pirating Lady Gaga?
Ron Marks, who spent 16 years with the CIA, says that to understand what made it possible for Manning to get his hands on so much, you have to go back to Vietnam.
In those Cold War days, information was chopped up and compartmentalized into bits and pieces. The idea was that if no good guys saw the big picture, no bad guys - the Soviets - could see it, either, said Marks, who is now a Senior Fellow at George Washington University's Homeland Security Policy Institute.
Back then, the U.S. military thought mostly about military power. It hadn't thought through much about how to deal with local populations or insurgents.
"That was one of the problems," Marks said. "We didn't know the people in the countryside. We didn't know the culture, or we really wouldn't have the kind of intelligence about who was playing with the Viet Cong and who wasn't."
From Vietnam, the U.S. learned that combat was a lot more complicated than dropping bombs; that it was also about having on-the-ground intelligence.
And in the '90s, the Pentagon started pushing high technology in warfare, so the computers and networks that kept all that information became as important as tanks and radar.
Then came the real kicker: September 11, 2001.
The 9/11 Commission concluded that the U.S. missed the events that led to 9/11 because agencies weren't sharing information with one another. That led to a complete overhaul in how the U.S deals with intelligence.
"It stopped being need to know - to need to share - I would say pretty quickly after 9/11," said Margaret Henoch, a former senior CIA official on the operations side.
When the U.S. went to war in Iraq and Afghanistan, "need to share" was the mantra, especially for troops on the battlefield.
"That might include knowing about local tribes," Marks said. "About outsiders who might be coming into the area. There might be outside fighters. So the idea is for the analyst to provide information to the soldier in the field so that they can use it in terms of their own smarts about what's going on around them."
And that "need to share" thinking led to military intelligence guys, like Manning, having access to reams and reams of information.
So did Manning need all that stuff to do his job? In Iraq, his job as an intelligence analyst was to analyze open-source and classified information on the Shia community in Iraq. But he had access to a lot more information than that.
Manning is accused of stealing documents from databases on Iraq and Afghanistan, records from the U.S. Southern Command, plus a quarter of a million records from a State Department diplomacy database.
Those range from cables on the Saudi monarch to the ambassador to Mexico.
"What did he need that for?" Henoch asked. "He's in charge of everything? He was a low-level guy!"
Henoch doesn't believe that sharing is necessarily a good thing, and she says Manning is the prime example of that.
"Bradley Manning didn't need anything about Saudi Arabia. I'm guessing they could have restricted what he needed to do his job to about seven cables."
Henoch is an adherent of the old way of doing things, where people, as she puts it, stayed in their lanes. In those days, Manning probably would have been counting planes or spotting for roadside bombs, not sifting through diplomatic cables or databases about Afghanistan.
The CIA would have been doing strategic intelligence collection - working to get defense secrets from government sources. And the State Department would have been doing diplomacy. Period.
At Manning's hearing, government witnesses said he could access the Pentagon's classified computer system in Iraq with a single log-in. Two of the computers - including one that Manning used - had software that allowed a user to download data onto a CD.
Capt. Ashden Fein, the lead prosecution attorney, asked Capt. Steven Lim, who was an officer in Manning's chain of command in Iraq, what would have stopped someone in that office from downloading secrets onto a CD for his own use.
"There comes a level of trust that comes with Top Secret clearance," Lim replied.
Since the WikiLeaks leaks, the Pentagon has made some obvious changes, like barring downloading of classified data onto CDs and such, and it has added steps to audit and track the use of its classified computer system.
And the State Department stopped sharing those diplomatic cables on the classified system that Manning is accused of stealing from.
But the Pentagon is not pulling back from the notion of "need to share."
Pentagon spokeswoman April Cunningham wrote CNN: "It's important to note that this effort to improve security preserves the government's commitment to share the information needed by our troops. We are not going to restrict sharing with the right people."
Margaret Henoch and Ron Marks do agree there will always be a Bradley Manning. Or spies like Robert Hansen. Or Aldrich Ames.
But they differ on what that means. Henoch says that's why there should be limits to what people like Manning need to have.
"Your assumption is there's always going to be a bad apple. So to make sure somebody doesn't do the kind of excessive damage that Bradley Manning did, you limit what that person has access to, to what he or she needs to do his job."
Ron Marks believes more in the current way of doing things. But he admits there are enormous risks that come with it. For one thing: There's not the time or money or manpower to filter out the documents that Manning may have needed to do his job, from the thousands of others. So Manning got them all.
"Are you able to separate out the stuff that he needs from what he doesn't?" Marks asked. "No. So we really are vulnerable."
That brings it back to the Pentagon's statement about sharing with the right people: It all comes back to the age-old question: Who do you trust?
CNN's Larry Shaughnessy contributed to this report.