The US has charged two people, one a naturalized US citizen, the other an Iranian national, with a plot to assassinate Saudi Arabia’s ambassador to the United States, from the Wall Street Journal:

Prosecutors filed several criminal charges against Manssor Arbabsiar, a 56-year-old naturalized U.S. citizen who holds Iranian and U.S. passports, and Gholam Shakuri, described as a member of a special-operations unit of the Iranian Islamic Revolutionary Guard Corps.

Mr. Holder said Mr. Arbabsiar and his Iran-based co-conspirators had been plotting to assassinate the Saudi ambassador since the spring.

A spokesman for Iran’s mission to the United Nations in New York said, “We categorically reject these baseless allegations.” Mr. Arbabsiar is scheduled to make a court appearance later Tuesday. It wasn’t clear if he had a lawyer.

Mr. Arbabsiar, who was arrested at John F. Kennedy Airport in New York on Sept. 29, has confessed to his involvement in the plot, while Mr. Shakuri remains at large, the Justice Department said.

So, the US charges and arrests one man, who at least is partially a citizen, holding both Iranian and US passports, and simply charges another, who is an Iranian citizen and remains at large?  Why didn’t the US just kill them?  Where is the substantive difference between these guys and the two American citizens recently executed by armed drone?  Is it because executing these two might stir the tempest a bit more than desired, and with a more formidable foe (Iran) than executing the two al Qaeda operatives in Yemen did?  Yemen is fairly close to a failed state, so who can meaningfully object to executions carried out by the US on its soil?  But these guys, or at least one of them, was in the US, where he was arrested.  What could Iran have done if the US had decided to summarily execute him as he stepped off the plane? 

Is it that the vaunted US Constitution applies when and where the US decides it applies?  Or is there some profound difference between killing people on American soil and killing them on foreign terrain?  If so, it won’t take long for al Qaeda to figure out that it should base its operations in the US. 

The real difference is that the American/Iranian had valuable intel, and the members of al Qaeda in the Arabian Peninsula, even if they might have valuable intel, can no longer be tortured to retrieve it, and end up occupying space in Guantanamo practically forever if they are captured.   So when Obama took his moral stand, saying he would eliminate torture and shut down Guantanamo, what he really meant is that he would kill suspected enemies of America such that no new inmates were added to the prison, such that presumably it would empty itself through attrition. 

Moral stands in international relations, where there is no morality except that of the jungle, can be rather sticky affairs.