WASHINGTON -- On Tuesday morning, the Supreme Court will hear oral argument on whether corporations, like real people, can be held liable in American courts for international human rights violations.

The issue has divided four appeals courts over the past year and a half, as all but one Democrat-appointed judge has voted for corporate liability while all but one Republican-appointed judge has come down for corporate immunity.

If that pattern holds in the Supreme Court, then the five justices appointed by Republican presidents will surely be hit with more accusations of pro-business bias: Having all voted in Citizens United v. Federal Election Commission to extend to corporations the First Amendment right of actual people to independently spend unlimited sums in this country's elections, they will in the current case have refused to hold corporations responsible, as real people are, for their roles in atrocities abroad.

That kind of application of corporate personhood would be enough to make a casual observer's head explode.

Legally, however, Tuesday's case, Kiobel v. Royal Dutch Petroleum, is totally unrelated to the Citizens United decision. What the Court decides, at least in theory, should have everything to do with how the justices approach international law.

In Kiobel, about a dozen Nigerians contend that Shell Oil's parent company aided and abetted their government in its torture and extrajudicial killing of environmental and human rights protesters resisting Shell's operations in Nigeria in the 1990s.

The plaintiffs brought their suit under a law, commonly called the Alien Tort Statute, passed by the first Congress in 1789 to allow foreign nationals to bring civil suits in federal courts "for a tort only, committed in violation of the law of nations or a treaty of the United States." The Alien Tort Statute lay virtually dormant from its founding-era passage until the 1970s, when human rights groups representing victims of oppressive regimes began taking advantage of the law's broad language to haul the alleged foreign tormentors before U.S. judges.

The Supreme Court has weighed in only once on the meaning of the law, stepping into the fray in 2004 to declare that only international law offenses that are as "specific, universal and obligatory" as those that existed when the statute was written could give rise to a lawsuit under the statute. Torture and genocide triggered the Alien Tort Statute, the Court suggested; arbitrary arrest and detention did not.

The justices left unsettled what types of defendants -- individual, corporate, state -- can be sued. The text of the law is silent on that issue.

In deciding Kiobel in 2010, the majority in the U.S. Court of Appeals for the 2nd Circuit divined its answer by asking whether any international courts have held corporations liable for human rights violations. Finding no such examples, the majority threw out the case.

Three other appeals courts have since disagreed with the 2nd Circuit in methodology and result when hearing cases under the Alien Tort Statute against Firestone, Exxon and Rio Tinto. These courts found that the question of corporate liability is up to individual countries to determine and that the U.S. domestic law has long held corporations to account for the wrongs they commit.

The United States, for its part, submitted a brief to the Supreme Court supporting the Nigerian plaintiffs. "The text and history of the ATS provide no basis for distinguishing between natural and juridical persons," the brief says, referring to the distinction between human beings and "persons" created under law. "Corporations have been subject to suit for centuries, and the concept of corporate liability is a well-settled part of our 'legal culture.'"

The real trouble for the justices hearing Kiobel is that nothing is "well-settled" under the Alien Tort Statute. The methods used by the lower courts to come to their opposite conclusions were not much more than newly created paths custom-beaten to lead to their preferred result. Now there is a veritable parade of ideologically driven parties, from multinational corporations and human rights organizations to conservative and liberal legal academics, who have submitted friend-of-the-court briefs hoping to lure the justices toward their favored destinations.

In an ironic twist, the conservative justices, who loudly resist being influenced by foreign legal trends, can look to European interpretations of U.S. law as the best cover for now discovering corporate immunity from international human rights allegations. In briefs filed in support of Royal Dutch Petroleum, the United Kingdom and Netherlands governments wrote that they have long opposed "overly broad assertions of extraterritorial civil jurisdiction" based on foreigners' claims against foreign defendants for alleged activities in foreign countries. The German government took a similar stance. These positions arose out of all three nations' express preference for multilateral agreements to resolve such problems, rather than unilateral action by any one country's courts.

Bluntly relying on these kinds of policy preferences may be a better path for the Supreme Court than pretending to fashion a decision out of nonexistent precedents and ideologically rigged legal arguments. Doing so will not eliminate the accusations of pro-business bias, but it will deter the accusations of disingenuousness that still plague the Citizens United decision.

Tuesday's oral argument should offer some hints at which path the justices will likely choose.

