The 1st Amendment applies to US citizens and non-citizen US permanent residents. It does not apply to foreign nationals. AFAIK Assange is not and was not a US permanent resident, so the 1st Amendment doesn't apply to him.
That being said, it would be difficult to convince me that the actions of Assange and Wikileaks rise to the level of espionage. None of what I've seen would indicate that he's actually done that.
That being said, it would be difficult to convince me that the actions of Assange and Wikileaks rise to the level of espionage. None of what I've seen would indicate that he's actually done that.