In public speeches, administration officials have criticized the use of the word “assassination” to characterize targeted killings carried out by the United States. The administration’s theory (or part of it, anyway) seems to be that targeted killings can’t be assassinations because assassinations are unlawful killings — and the US’s targeted killings, in the administration’s view, are lawful. In response to litigation, the administration has released legal memos that spell out this seemingly circular argument in more detail. The relevant portions of the memos, however, are heavily redacted. Below, I try to piece together what we know, and I discuss what we might learn soon.

The assassination ban was put into place after the issuance of the 1975 Church Committee Interim Report which summed up the Committee’s investigation of, among other things, US-backed assassination plots against foreign leaders. The report concluded that the CIA had attempted to assassinate the leaders of Cuba and the Congo, and that it had aided assassination plots in the Dominican Republic, Chile, and Vietnam. Noting that “[a]dministrations change, CIA directors change, and someday in the future what was tried in the past may once again become a temptation,” the report recommended that Congress ban assassination. Concerned that Congress might do so, President Ford issued Executive Order 11905 which included this language: “No employee of the United States Government shall engage in, or conspire to engage in, political assassination.” Subsequent orders by Presidents Carter and Reagan reaffirmed the ban, albeit with modifications. The current version of the ban, in Executive Order 12333, states: “No person employed by or acting on behalf of the United States Government shall engage in, or conspire to engage in, assassination.”

The language of the ban is simple enough but its meaning has long been contested, mainly because the term “assassination” is nowhere defined. Is the ban limited to peacetime killings of public officials or leaders? Is it limited to “political” killings — and, if so, what killings are properly termed “political”? Does the ban proscribe killings carried out in defense of the nation? Can one reasonably interpret the ban merely to incorporate or reaffirm prohibitions that are stated elsewhere in domestic or international law, as a 1989 Department of Army memorandum (known as the Parks Memo) suggests? If one interprets the ban this way, is it fair to call it a “ban” at all?

Every administration since President Ford’s seems to have considered the assassination ban’s scope and meaning. Bob Woodward and Walter Pincus reported in 1988 that President Reagan issued four directives relating to the assassination ban over a period of 18 months. The first, issued in November 1984, was designed to circumvent the assassination ban by preemptively declaring “lawful” any actions that were undertaken “in good faith and as part of an approved operation.” Dubbed a “license to kill” by Woodward’s sources, the November 1984 authorization may have led to an attempt to kill Lebanese cleric Mohammed Hussein Fadlallah, who the Reagan administration suspected of having ties to Hezbollah — an attempt that left Fadlallah unscathed but killed 80 bystanders. President Reagan rescinded the “good faith” language in April 1985 but reinstated it less than six months later, after the hijacking of TWA flight 847. The congressional committees charged with overseeing covert activities then forced the administration into retreat once again and the administration removed the “good faith” language for a second time in the spring of 1986.

The 9/11 Commission Report indicates that President Clinton issued multiple directives relating to the assassination ban in connection with the proposed or actual use of force against Osama bin Laden in 1998 and 1999. One directive reportedly stated that lethal force could be used only in self-defense, and only in the context of a capture operation. Another, however, reportedly took a far broader view of presidential power, concluding that

recent presidents—from Reagan in Libya to Bush in Iraq—had been needlessly cautious in ordering broad attacks against enemy headquarters if their real objective was to kill an individual leader. Because executive orders are entirely at the discretion of the president … a president may issue contrary directives at will and need not make public that he has done so. Under customary international law and Article 51 of the U.N. Charter, according to those familiar with the memo, taking the life of a terrorist to preempt an imminent or continuing threat of attack is analogous to self-defense against conventional attack.

The Obama administration has interpreted the assassination ban, too. Recently, the New York Times reported that the Obama administration produced five legal memos in anticipation of the May 2011 raid on the bin Laden compound in Pakistan. The New York Times report does not mention the assassination ban specifically, but it is a safe bet that lawyers charged with developing “rationales intended to overcome any legal obstacle” took the ban into account.

Unfortunately, all of these analyses of the assassination ban are secret. As a result, we know little about how the Obama administration interprets the assassination ban, let alone how its interpretation differs from those of previous administrations. We also lack the information we need to evaluate the significance of the Obama administration’s assurances that targeted killings aren’t assassinations.

It’s possible, though, that we will learn more in the coming weeks. An ACLU Freedom of Information Act suit pending before the Second Circuit challenges the withholding of two Office of Legal Counsel memos that we know address the assassination ban. One of them is a March 2002 memo that the government acknowledges “provid[ed] advice concerning the assassination ban.” The other is a February 2010 memo that concluded that the assassination ban posed no obstacle to the use of lethal force against American citizen Anwar al-Aulaqi, who was killed in a drone strike the next year. The government released a version of that opinion to the ACLU last year, but the sections that address the assassination ban were redacted.

Of course we don’t know whether the Court will order the government to release either of these documents. The discussion at oral argument, however — and the transcript of an unusual ex parte hearing held with the government — suggest that at least one judge was troubled by the withholding of certain portions of the 2002 memo. Last week, the Court filed a sealed ruling addressing these records. (The Court sealed its ruling to give the government an opportunity to seek further review.) Let’s hope that the Court requires the disclosure of at least some of the withheld analysis.

It has been more than five years since the ACLU commenced its FOIA litigation, and more than two years since President Obama pledged to make the program “more transparent to the American people and the world.” A public accounting of the administration’s view of the assassination ban is long overdue.