Citizenship expert Peter J. Spiro gives a bit more detail on the process for relinquishing citizenship. He says it might be constitutional, but Sen. Joe Lieberman's proposal to strip citizenship from suspected terrorists still wouldn't work:
Now, these rulings do allow the government to terminate citizenship on the basis of conduct alone, without a formal renunciation before a consular officer, so long as that conduct reflects a specific intent to relinquish citizenship. It was (consistent with Terrazas) long presumed that naturalization in another state reflected a desire on the part of individual to shed his US citizenship. That’s no longer the case. As a matter of administrative practice, the State Department since the 1990 has presumed individuals intend to retain their citizenship except where they expressly renounce before a US consular official. This is true even if the oath of naturalization in another country includes an express renunciation of US citizenship. Service in a foreign military? Not a problem, Lieberman’s implication to the contrary.
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I don't expect this to become law, and if it does, it won't be put to much work. This is more anti-terror showboating than anything else.
CAP's Ken Gude also has a response, calling the proposal a"gimmicky political stunt":
Unfortunately, citizenship status has no bearing on requirements to advise suspects of their rights under the Miranda rule, and in any event, such actions do not interfere with intelligence collection. Making it worse, when the Bush administration tried interrogation Sen. Lieberman's way, it was a spectacular failure. The Obama administration should reject these gimmicky political stunts and keep the pressure on terrorist organizations using all the weapons in our arsenal, including the tough and proven criminal justice system, to identify and defeat terrorists.
The point of culture-war counterterrorism isn't security. It's a ritualistic banishing of the bogeymen, a quixotic crusade for satisfaction through indiscriminate and premature punitiveness. It's not supposed to make you safer; it's supposed to make you think you're safer.
-- A. Serwer