Earlier quoted context omitted.
What good would assassinating him do? He's not the only one who runs Wikileaks or has access to the information. They'd need to "snatch" everyone who has access to it, which might be a very difficult proposition, not to mention a complete public relations disaster, considering Wikileaks is in the public spotlight right now. I very much doubt the CIA is holding back out of the goodness of their hearts. No. What we are…
I'm not suggesting they assassinate him. He's broken numerous laws and they have a pretty compelling case against him. I can't imagine that the public relations fallout from his arrest would be any worse than the public relations disaster they have with the release of these cables.
Are we still talking about the CIA? Has it become a law-enforcement agency and I didn't notice?
If your point is regarding the possibility of the US government going after Assange by legal means (not via some extralegal, shadowy CIA antics), I'm certain they would if they could.
The fact that they haven't leads me to believe their case against him isn't quite as airtight as you believe.
But regardless of what they do or try to do to Assange, it won't stop Wikileaks. The best that the US government could manage is to extract some sort of retribution or send out a warning to future leakers and whistleblowers.