Julian Assange and Wikileak’s case is indistinguishable from the Pentagon Papers case. From Alan Dershowitz at theburningplatform.com:
Before WikiLeaks founder Julian Assange gained asylum in the Ecuadorian Embassy in London in 2012, he and his British legal team asked me to fly to London to provide legal advice about United States law relating to espionage and press freedom. I cannot disclose what advice I gave them, but I can say that I believed then, and still believe now, that there is no constitutional difference between WikiLeaks and The New York Times.
If The New York Times, in 1971, could lawfully publish the Pentagon Papers, knowing that it included classified documents stolen by Rand Corporation military analyst Daniel Ellsberg from our government, then WikiLeaks was entitled, under the First Amendment, to publish classified material that Assange knew was stolen by former Army intelligence analyst Chelsea Manning from our government.