From the NYT [0]:

"The disclosures set off a frantic scramble as Obama administration officials sought to minimize any potential harm, including getting to safety some foreigners in dangerous countries who were identified as having helped American troops or diplomats. Prosecutors, however, presented no evidence that anyone was killed because of the leaks."

So no one was killed, but it does seem to have put people at risk.

0: https://www.nytimes.com/2017/01/17/us/politics/obama-commute...

That's what they _said_, yes. Remember the rhetoric of the time-- distinguished government officials said both Manning and Snowden had "blood on their hands". Manning was in custody, but multiple senators and representatives called for Snowden to be assassinated.

In summary, I'm gonna need to see some actual proof.

Even assuming anyone could actually know this, the real damage is going forward. FSOs gather a lot of information just by talking to people, and people are going to be very circumspect if they think what they say will be repeated to the world with attribution. How much would you say to a friend or relative if you knew the first thing they'd do is put up a Facebook post with whatever you told them?

How do you know?

The prosecution admitted as much at her trial. Read up on United States vs Manning for more details.

I agree. It will make it seriously difficult for anyone to discuss with a US diplomat in confidence given that the guy will log it in his little secure system and that the transcript will be on the web within 5 years. Not really worth risking your life.

I think it is safe to assume this leak will have seriously affected the US diplomacy.

I believe that we would definitely have been told if there was.