Is bombing power plants and oil facilities a war crime?

Even as america and Iran talk about more peace talks, Donald Trump is still raising the prospect of bombing Iranian infrastructure. “I would hate to do it, but it’s their water, their desalinisation plants, their electric-generating plants, which are very easy to hit,” said the American president on April 12th.

America’s armed forces are sworn to defend the constitution, which names the president as their commander-in-chief whose orders they should ordinarily obey. Yet international laws of war also direct them to disobey “manifestly unlawful” orders. The instruction from Pete Hegseth, the secretary of war, to show “no quarter, no mercy” to incapacitated enemies, is expressly forbidden in international law. But what of attacks on bridges, power stations and oil facilities?

The laws of war state that civilian facilities are not lawful targets unless they pass three tests. The first is that they are being used for military purposes and that attacking them will provide a “definite” military advantage. The term “definite” is not precise, but suggests that the advantage cannot be speculative. That means that bridges used to move troops or ammunition, or power stations that provide electricity to radar stations, could be targets.

The next test is whether everything feasible has been done to minimise harm to civilians. Before striking a power station used by civilians and, for instance, an air-defence site, an attacker would have to examine whether it could instead cut power to the air defences by attacking, say, a substation or power line leading to it.

Last, the attacker has to pass a proportionality test, meaning that any expected civilian harm is not excessive in relation to the anticipated military advantage. By that test some bridges or power plants might be considered lawful targets. “When I was a targeting officer back in the last century, we always went after bridges,” says Michael Schmitt, formerly an American air-force officer and now a law professor at the University of Reading. “But it was not every bridge. You would have to say that the enemy is using my bridge, or I know that the enemy will be using my bridge.”

But implementing Mr Trump’s threat to destroy desalination plants, which are essential for sustaining civilian lives, or all bridges and power plants, would be clear breaches of international law. So is Israel’s indiscriminate destruction of buildings and homes in Gaza and Lebanon on the basis that they might be used by Hamas or Hizbullah. America’s blockade of Iran’s ports, though an act of war, is legal.

It is, however, less clear whether blowing up oil facilities would be a war crime, at least under American law. Most countries consider attacks on purely economic infrastructure unlawful, but America claims the right to attack “war-sustaining” targets that generate finance for the enemy. It was on this basis that America bombed drug labs in Afghanistan and, along with allies including Britain and France, struck oil wells controlled by ISIS in Syria.

Mr Hegseth breezily dismisses the laws of war as “stupid rules”, but his subordinates and allies are more troubled. American troops could be charged with war crimes, in America or abroad. Allies such as Britain could put themselves in legal jeopardy if they knowingly aid American breaches of international law by, say, letting bombers use British airfields.

Ironically, Mr Trump may turn out to be most shielded by the law, since his threats are so outlandish that he could claim he did not mean them literally. “My president has taken puffery to a high art form,” says Professor Schmitt. “That actually works to his benefit, because it’s difficult to give credibility to much of what he says.” ■