Is the rule of Law in the US Inoperative?

It was Richard Nixon's press secretary Ron Ziegler that made the word "inoperative" a part of American history (it was a euphemism for "We Lied").  Now during the Senate confirmation hearings for John Brennan as head of the CIA we hear echos of inoperative.
SEN. RON WYDEN: Let me ask you several other questions with respect to the president’s authority to kill Americans. I’ve asked you how much evidence the president needs to decide that a particular American can be lawfully killed and whether the administration believes that the president can use this authority inside the United States.

Brennan answers with total gibberish.

JOHN BRENNAN: I have been a strong proponent of trying to be as open as possible with these programs, as far as our explaining what we’re doing. What we need to do is optimize transparency on these issues, but at the same time optimize secrecy and the protection of our national security. I don’t think that it’s one or the other. It’s trying to optimize both of them. And so, what we need to do is make sure we explain to the American people what are the thresholds for action, what are the procedures, the practices, the processes, the approvals, the reviews. The Office of Legal Counsel advice establishes the legal boundaries within which we can operate. It doesn’t mean that we operate at those out of boundaries. And, in fact, I think the American people will be quite pleased to know that we’ve been very disciplined, very judicious, and we only use these authorities and these capabilities as a last resort.

If ever there was the epitome of obfuscating bureaucratic blather, Brennan achieved it in pointedly not ruling out the killing of US citizens on US soil.

So what is the answer to Wyden's question?  What are the rules?  Will they just kill anyone they deem dangerous, no matter where?