This story doesn't disclose a single named source. I don't have enough faith in any media outlet to believe any story that can't be verified.
There's no way for anyone to begin checking it. A western diplomat could be any of a thousand people from any country west of Poland.
I can't think of anything to do with this story except say it might be true.
To paraphrase him on OBL:
"We know more than we are telling....."
Doesn't seem to matter to most people. Even here at FR.