Peter is involved in international human rights issues because he still believes that we can achieve a world governed by the rule of law, where international human rights violations can be prosecuted anywhere in the world.  His book, Human Rights and the Alien Tort Statute: Law History and Analysis, was published by the American Bar Association in 2009. 

The horrors of World War II created a consensus among the nations of the world that the relationship between a government and its citizens is a matter of international concern, and that organizations such as the United Nations were needed to provide a permanent venue to address international problems and concerns without resorting to war.  The Holocaust and other atrocities committed by supposedly "civilized" counties demonstrated that genocide and crimes against humanity affected the entire world.  The unprecedented number of casualties from war crimes, including the bombing of civilian populations, were also plainly a matter of international concern.  It is no longer acceptable for brutal and repressive governments to murder their own citizens, torture them, or take other actions that are deemed to violate an international consensus of minimum acceptable standards of conduct.  International law, as embedded in the International Declaration of Human Rights and International Covenant on Civil and Political Rights, now addresses the relationship between a country and its citizens.

In 1980, in the case of Filartiga v. Pena-Irala, a Paraguayan police captain was found liable for torturing and killing the 17-year-old son of a political opponent of dictator Alfredo Stroessner.  Judge Irving Kaufman famously declared that "the torturer has become like a pirate and slave trader before him hostis humani generis, an enemy of all mankind."  The court established three important principles:

1. United States courts have jurisdiction under an obscure 18th century statute, the Alien Tort Statute, to adjudicate violations of international law, even though neither of the parties are United States citizens.

2. International law is continually changing.  A court must apply contemporary international law to claims brought under the Alien Tort Statute.

3. Customary international law prohibits a government from torturing its own citizens.

In 2004, the Supreme Court upheld the basic holdings of Filartiga in Sosa v. Alvarez-Machain.  It is now clear that human rights cases alleging a violation of international law can be prosecuted in United States courts.  The nations of the world will continue to reach consensus on norms of internationally accepted conduct and these norms can be enforced in United States courts. 

Since Filartiga, there have been hundreds of cases brought in United States courts, alleging violations of international law.  Cases under the Alien Tort Statute have alleged violations of international human rights on every inhabited continent, and for a wide range of activities: Nazi-era atrocities, ethnic cleansing and genocide, suppression of religious groups, war crimes committed with the approval of governments, terrorism, and torture and extrajudicial killing by the agents of brutal dictatorship.  In addition, there is a growing consensus that other types of misconduct by governmental actors, such as state sponsored discrimination on the basis of race, gender, and possibly even religion, may also violate international law.  Similarly, expropriation of property by governmental actors without compensation, forced exile, and involuntary medical experimentation have also been found to violate international law.

Cases brought against government actors are frequently barred by immunity doctrines.  For example, a case brought against Robert Mugabe, the virtual dictator of Zimbabwe, was dismissed because, as a sitting head of state, he was entitled to a common law immunity from civil litigation.  Israeli governmental officials have been found to be immune for alleged war crimes in Lebanon and Gaza because the alleged actions were part of official governmental policies.  Similarly, U.S. officials, including Henry Kissinger, have been entitled to immunity for alleged violations of international law in Chile and Latin America.

In a 1995 case, Kadic v. Karadzic, the Second Circuit held that Radovan Karadzic, the self-styled President of the Republic of Serbia, could be sued as an individual for his involvement in the atrocities in Bosnia even though he was not acting as a governmental official.  This case was very important because it established the principle that private individuals and, by implication, other non-governmental actors such as corporations, could be found liable for violating international law.  Kadic opened the door to lawsuits against multinational corporations for committing human rights abuses and for aiding and abetting such abuses by governments. 

Kadic enabled a new wave of cases under the Alien Tort Statute, particularly against oil and mining companies for assisting brutal governmental repression.  In the most successful case, Unocal paid a settlement, reportedly in the amount of $30 million, for its actions in constructing a pipeline through Myanmar, because the Myanmar military committed gross human rights violations. In South African Apartheid Litigation, a case that is being actively litigated in the Southern District of New York, plaintiffs are seeking to hold a group of multinational corporations liable for aiding and abetting the apartheid policies of the former Union of South Africa.