In the wake of the recent confirmation hearing on John Brennan's nomination as CIA director, and the probably related "leak" of a Justice Department white paper on targeted killings, some politicians, pundits and professors have suggested that "kill lists," drone strikes and targeting protocols be submitted for "independent judicial review" — essentially, that federal judges ought to be assigned the task of monitoring, mediating and approving the killer instincts of our government. This is a very bad idea.

U.S. judges have been hardwired against rendering "advisory opinions" since 1793, when the first chief justice, John Jay, declined to answer President George Washington's legal questions about the status of a British ship that had been captured by the French and brought to an American port.

To answer the president's questions, Jay wrote, would violate "the lines of separation drawn by the U.S. Constitution between the three departments of the government." Jay's letter referred to Article II, Section 2 of the constitution, which provides that the president "may require the opinion, in writing, of the principal officer in each of the executive departments, upon any subject relating to the duties of their respective offices" — a provision, Jay wrote, that "seems to have been purposely as well as expressly united to the executive departments."