I had never seen this purported quote before. And I found it extremely dubious that he said such a thing. Seeing as you didn't provide a source I went looking for one. I found first a recent NYT piece [1] with the purported quote. Here's the first paragraph of that piece :
> Fourteen years ago, at a human rights conference in Oslo, I met Julian Assange. From the moment I encountered the wraithlike WikiLeaks founder, I sensed that he might be a morally dubious character. My suspicions were confirmed upon witnessing his speech at the conference, in which he listed Israel alongside Iran and China as part of a “rogue’s gallery of states” and compared the Guantánamo Bay detention facility to a Nazi concentration camp
I think it's pretty obvious from that opening that it's a hit piece on Assange. Anyway, that piece links to an earlier Guardian piece [2] for the source of the quote. That Guardian column is another, and even more obvious, hit piece on Assange. Here's its first paragraph :
> You did not have to listen for too long to Julian Assange's half-educated condemnations of the American "military-industrial complex" to know that he was aching to betray better and braver people than he could ever be.
Vomit. But finally in the Guardian piece we find the source of the purported quote. It's from David Leigh and Luke Harding's "history" of WikiLeaks. I think most people who have closely followed the Wikleaks story will understand how unreliable and compromised both David Leigh and Luke Harding are to serve as 'witnesses' or sources for any reporting on Wikileaks and Assange. But they've served their masters very well as yellow journalists engaged in a state backed smear campaign against Assange.
> Fourteen years ago, at a human rights conference in Oslo, I met Julian Assange. From the moment I encountered the wraithlike WikiLeaks founder, I sensed that he might be a morally dubious character. My suspicions were confirmed upon witnessing his speech at the conference, in which he listed Israel alongside Iran and China as part of a “rogue’s gallery of states” and compared the Guantánamo Bay detention facility to a Nazi concentration camp
I think it's pretty obvious from that opening that it's a hit piece on Assange. Anyway, that piece links to an earlier Guardian piece [2] for the source of the quote. That Guardian column is another, and even more obvious, hit piece on Assange. Here's its first paragraph :
> You did not have to listen for too long to Julian Assange's half-educated condemnations of the American "military-industrial complex" to know that he was aching to betray better and braver people than he could ever be.
Vomit. But finally in the Guardian piece we find the source of the purported quote. It's from David Leigh and Luke Harding's "history" of WikiLeaks. I think most people who have closely followed the Wikleaks story will understand how unreliable and compromised both David Leigh and Luke Harding are to serve as 'witnesses' or sources for any reporting on Wikileaks and Assange. But they've served their masters very well as yellow journalists engaged in a state backed smear campaign against Assange.
[1] https://archive.md/FV0N0
[2] https://archive.md/5kSgB