Before the government can tap the phone or read the e-mails of an American suspected of having terrorist links, it must get the approval of a federal judge. But if they target the same person for death, no such review pertains.

And that deeply concerns Vicki Divoll, a former CIA officer and Senate Intelligence Committee lawyer, who now teaches U.S. government and the Constitution at the U.S. Naval Academy, and who will speak on the subject of targeted killings of Americans by the Obama Administration, tomorrow at the Chilmark Public Library.

And her concern is not simply a theoretical one. There is strong evidence to suggest at least one American citizen, Anwar al Awlaki, a Muslim cleric born in New Mexico and now believed to be in hiding in Yemen, is on the CIA list of suspected terrorists who may be captured or killed.

Earlier this year, media reports citing unnamed intelligence and counter-terrorism sources, said al Awlaki was on the list. There has been no official denial. Indeed, in a recent interview (in the Washington Times on June 24), the deputy White House national security adviser, John O. Brennan, spoke of “dozens” of Americans abroad who posed a terrorist threat.

He did not directly say they were on any kill list, but he did say this:

“To me, terrorists should not be able to hide behind their passports and their citizenship, and that includes U.S. citizens, whether they are overseas or whether they are here in the United States.

“If an American person or citizen is in a Yemen or in a Pakistan or in Somalia or another place, and they are trying to carry out attacks against U.S. interests, they also will face the full brunt of a U.S. response. And it can take many forms,” he said.

“To me, John Brennan sounds like he is tacitly confirming there are Americans on the list,” said Ms. Divoll.

She hastened to add that her former employment with the CIA and the Intelligence Committee gave her no inside information, but said if it is true the tactic of targeted killings of Americans is a concerning new development in America’s response to the threat of terrorism.

And one which might give pause to those who hoped for greater executive restraint under the Obama administration, compared with that of President Bush.

“We have no knowledge that president Bush ever put an American on the list,” she said.

Her concerns are twofold: first with the generic practice of targeted killings, and second, particularly, with the legality of doing it to U.S. citizens.

“My view on targeted killing generically is that although legal and appropriate perhaps inside a war zone, the targeted killings of foreigners outside war zones — for example the cross-border operations in Pakistan — are bad policy and unethical under Just War ethics,” she said.

“It is not unlawful under U.S. law. I’m not as familiar with international law, so I don’t want to comment on that. But as a former United States government lawyer, I note it is not illegal.

“That, however, doesn’t mean it’s a good idea. We don’t know whether it’s good policy, whether it’s effective in achieving our ultimate goals. We don’t know exactly what we’re doing or where we’re doing it because it is unacknowledged by the government.

“Just War ethics is a moral code of war fighting that’s been around for centuries, which is a way of judging the legitimacy of tactics used by government. The United States purports to follow those ethical norms, but I would argue that cross-border operations with targeted killings by unmanned drones does not follow those norms.”

But the questions about killing foreign people in foreign countries are quite different from those around doing the same to American citizens. The former, she said is an ethical and policy issue; the latter is a Constitutional and legal one.

“As to the issue of whether U.S. courts should be involved when we start putting Americans on the list, I am suggesting that (a) there might be Constitutional questions and (b) even if there aren’t, Congress should step up and make it illegal.”

As Ms. Divoll succinctly put it in an opinion piece in the Los Angeles Times on April 23: “As a matter of U.S. law, had the administration wanted merely to listen to Awlaki’s cellphone conversations or read his e-mails, it would have needed to check with another branch of government — the judiciary. But to target him for death, the executive branch appears to have acted alone.

“It adds up to this: Awlaki’s right to privacy exceeds his right to life.”

Speaking from her Chilmark summer home yesterday, Ms. Divoll said the proper approach to a U.S. suspect was to target him for intelligence or law enforcement purposes, unless, of course, he was actually on the battlefield.

“If Awlaki is in Afghanistan fighting side by side with the Talban and he gets killed, that’s the way it goes. He’s waging war.

“But if he is sitting in Paris and making decisions about various things, I think we have an obligation to collect as much intelligence about him as we lawfully can and to try to capture him.

“When it comes to Americans, I think the Constitutional protections that we afford [should ensure] American citizens should get the benefit of any doubt.”

She noted that intelligence is often wrong, and referred, as an example of how easily errors are made, to the case of Khalid El-Masri, a German citizen, who was detained in Macedonia in December 2003, handed over to the CIA, taken by extraordinary rendition to Afghanistan and allegedly tortured. He was finally released on May 28, 2004, after it was realized he had been mistaken, due to a spelling error, for a terrorist. He was dumped at night on a deserted road in Albania, without funds or apology.

“To be making life or death decisions based on intelligence information, much of which is provided by people with an axe to grind, and which is not tested by courts, is a terrible way to do business against our own citizens,” she said.

Surely, though, if it was legitimate for Congress to insist on some kind of judicial oversight of targeted killings of Americans, the same restrictions should be applied to all targeted killings? Foreigners are at least as likely to be the innocent victims of error as Americans.

But that point, she said, went to her broader objections to the ethics of targeted killings, not to U.S. law.

“That perhaps would be going too far,” she said.

“It could be an infringement on the executive power to wage war. When you’re killing foreign people in foreign countries, Congress doesn’t have a whole lot of say in it beyond that you do it and where you do it. Once Congress has said ‘go do a war’ — which you could argue they have or haven’t in this case — their job is done.”

After that it’s up to the executive.

“So, no, I don’t think there should be a law having a judge look at foreign persons.

“Just Americans,” Ms. Divoll said.