Is the U.S. military bound by the same environmental laws as the country being occupied? Let's say that the United States is still occupying Afghanistan, to what extent does the U.S. military have to abide by the environmental laws of the country. I am not talking about individuals committing a felony against an individual of the occupied people, but rather the military as an institution or as an occupying force. Example, let's say that the U.S. military in Afghanistan wants to burn down equipment and goods containing petrochemicals and other highly toxic compounds, can the U.S. military do so even if it's against the environmental regulations of the country of Afghanistan? If they can't do so, who enforces the environmental laws, the government of Afghanistan itself or an international organization?
The U.S. military claims sovereign immunity and also has express exemptions from many (but not all) U.S. environmental laws. The local courts have no practical authority over the U.S. military forces and U.S. courts would not generally entertain a lawsuit to enforce foreign environmental laws against the U.S. military.
Usually, when U.S. forces are based in a foreign country with its voluntary permission, a Status of Forces Agreement is reached between that country and the U.S. government. The Status of Forces Agreement sometimes includes some environmental law requirements, but it rarely makes U.S. military forces fully subject to local environmental laws.
Military occupiers aren't bound by the rules of the nation they're occupying.
So, let's look at the realpolitik of the situation of military occupations, for a moment. If someone sends an army into your country to occupy it, it's an act of war, and governed by the laws of war in international law. Once that war's over, and they've successfully occupied your nation, then there's no one in your country capable of opposing them; not only are they unbound by the laws of your nation, they're able to forcibly impose whatever laws they desire onto your nation.
The only things stopping them from doing whatever they wanted would be the political calculus about things like potentially inciting general rebellion through overly draconian rules, a negative reaction from the people back in their home nation, or negative reactions from peer powers.
Sayaman's question is about military occupation which has a specific and unambiguous legal meaning. Conventions, treaties, customary law, and the domestic law of the occupier governs what the occupier can do to occupied territory. The probably most famous and most long-lasting example of a military occupation is Israel's occupation of the West Bank, Gaza Strip, and Golan Heights.
In Enhancing Environmental Protection During Occupation Through Human Rights Karen Hume analyses international law and existing state practice and concludes that the occupier has certain environmental responsibilities vis-a-vis the occupied territory:
Drawing on the examination of State practice above, the minimum core obligations of environmental human rights could be conceived as follows:
- Ensuring a baseline level of environmental health, so as to meet the needs of the population, such as adequate food and water sources, and a healthy life itself;
- Managing environmental risk, to ensure the collection and provision of environmental risk information; and
- Conserving a healthy environment in the broader, ecological sense.
Essentially, the occupier must not unduly harm the environment of the occupied territory. For example, it must not divert water resources, dump toxic waste, or spray herbicides unless there is a pressing military need. This is especially true if the domestic law of the occupied territory prohibits those actions because the occupier must respect the local laws in force in the country:
The authority of the legitimate power having in fact passed into the hands of the occupant, the latter shall take all the measures in his power to restore, and ensure, as far as possible, public order and safety, while respecting, unless absolutely prevented, the laws in force in the country.
Thus, your example of the U.S. military burning petrochemicals in Afghanistan would constitute a war crime.
Enforcement is a different matter. Perhaps an American soldier who caused ecological damage in Afghanistan would face a court-martial. However, if the ecological destruction was caused by a conscious military strategy, it is hard to see what body would be able to enforce a judgement against the U.S. military.
Environmental Laws are no different from any other laws
When the US (or any other) military occupies a country, their rule overrides any existing laws of the previous government. They are, temporarily, the "law of the land". While it might seem that "environmental law" is somehow different and special, it isn't. A law is a law is a law.
To take an extreme example, if a country has a law outlawing non-Muslims from living there and practicing their own religion, the US military would not abide by such a law. They might, out of respect for the civilian population (if that population is itself majority Muslim), refrain from any public practice of non-Muslim religion outside the military bases, but they could certainly allow Christian, Jewish and other non-Muslim US military personnel to practice their religion publicly within the base (e.g., chapel, group services, etc.) and privately off-base. That is different from when the US military has an agreement with another country to establish a base for mutually agreed reasons - e.g., US in Saudia Arabia during the first Gulf War.
The American Sector of Berlin was occupied by American troops for 45 years, from May 1945 until October 1990 (or maybe the occupation ended somewhat earlier during 1990? October was the time of reunification.).
German authorities actually governed the city. Except that occasionally something about the way they governed conflicted with the purposes of the occupying forces, who then overruled them.
American judicial power in the American Sector was vested in the United States Court for Berlin, whose judgeship was vacant until an odd incident in 1978. The U.S. had spent years trying to get East-Bloc countries, including Poland and East Germany, to sign a hijacking convention. After they finally succeeded, two East Germans, having learned that their plan to flee to West German had been discovered by authorities, used a desperate measure to flee before being arrested: they boarded a plane in Poland that was bound for East Berlin, and hijacked it to a destination only a couple of kilometers away in West Berlin. They didn't use an actual gun but rather a starting pistol. If they were not prosecuted, the hijacking treaty would be lost. But the local German authorities did not want to prosecute, since they supported efforts of East Germans to flee in defiance East German authorities. So the U.S. Court for Berlin became the trial venue, with an American judge and an American prosecutor and both American and German defense lawyers. One defendant walked for lack of a Miranda warning and the other was sentenced to time already served, which was about nine months. So what does this have to do with the question? The answer is that while the Court was in session, the occupying authorities wanted to build something that ran afoul of local zoning ordinances. The German authorities who enforced such ordinances were overruled by the occupiers. So their lawyers came up with a theory that that the U.S. Court for Berlin therefore had jurisdiction and asked it to act. Unfortunately for them, the business of the Court in the hijacking cases had just wrapped up, so the State Department then dissolved the Court and that was the end of that.
The judge, Herbert Jay Stern, wrote a book about it: Judgment in Berlin.