Is US Killing of Iranian General Soleimani an Illegal Act of War?

The US appears to be trying to claim this was preemptive self-defence, but the legal test may not be satisfied.

9 min read
The killing of Major General Qassem Soleimani (L) upon the orders of US President Donald Trump (R) is a violation of the UN Charter and international law. 

On Friday, 3 January, the world awoke to the news that the United States of America had killed Iranian Major-General Qassem Soleimani – the head of the Quds Force, the international arm of the powerful Islamic Revolutionary Guards Corps (IRGC) – in a drone strike at the Baghdad International Airport in Iraq.

The move can have massive geopolitical implications, as Soleimani was the key figure behind Iran’s involvement across the Middle East, and had also become perhaps the second-most powerful person in Iran, enjoying huge popularity among citizens.

Soleimani had helped Syrian President Bashar al-Assad survive the Syrian civil war, and played an important role leading Shia militias, which fought the Islamic State (IS) in Syria and Iraq.

In a statement by the Pentagon, the US claims that Soleimani “was actively developing plans to attack American diplomats and service members in Iraq and throughout the region” and that he and his Quds Force were responsible for the deaths of “hundreds of American and coalition service members and the wounding of thousands more.”

The US also claimed that Soleimani had orchestrated attacks on coalition bases in Iraq over the last few months, including a recent attack on 27 December, and also the attacks on the US Embassy in Baghdad over the last week. The drone strike which killed Soleimani (as well as Abu Mahdi al-Muhandis, deputy head of a major Iraqi Shia militia group), the US claims, “was aimed at deterring future Iranian attack plans.”

While Iran now threatens to retaliate and analysts scramble to understand what will happen next in the volatile region, an important question that must be asked – even though most will just brush it away – is whether the actions of the US are in accordance with international law or not.

Prohibition of Use of Force & Legality of Targeted Killings

One of the few rules of modern international law that has some sort of clarity is the prohibition of the use of force. Article 2(4) of the Charter of the United Nations says:

“All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.”

In her book on the subject, International Law and the Use of Force, Christine Gray, the leading scholar on this subject notes that the International Court of Justice has proclaimed the prohibition of the use of force to be a “cornerstone of the UN Charter”, and that the prohibition is not only a treaty obligation but also customary law and even ius cogens”.

What this essentially means is that there is little doubt that it is against the very basics of international law for a country to use armed force against another, unless it falls within the strict exceptions provided for this. Note that this does not only cover formally going to war, but any sort of armed attack.

The assassination by drone strike of an Iranian military leader during peacetime, even if it has taken place in another country, would be a use of force against Iran, as this affects the political independence of Iran and goes against the Purposes of the UN listed in Article 1, including the resolution of disputes peacefully.

On the face of it, this would mean the killing of Soleimani was a violation of international law when it comes to jus ad bellum – ie, the law of when States can go to war or use armed force against someone.

Such an assassination – what the US would term a ‘targeted killing’ – would also fall foul of international human rights law, which would be applicable since the US and Iran are not engaged in any sort of armed conflict.

UN Special Rapporteur on Extra-Judicial Killings Agnes Callamard has already put forth this argument, explaining how drones can be used for targeted killing only when “strictly necessary to protect against an imminent threat to life.”

The legal status of targeted killings using drone strikes under international human rights law and international humanitarian law (what constitute jus in bello, ie, the law relating to how you conduct warfare) is not entirely clear at this point of time. The US has used this approach for many years, starting with former President George W Bush, and actually intensifying during Barack Obama’s tenure in the Oval Office.

The US has previously claimed that such strikes satisfy relevant tests of necessity and proportionality, and would no doubt look to justify the strike that killed Soleimani, noting only eight people died in the attack. However, while this might help them with the arguments regarding jus in bello, it does not affect the seeming illegality under jus ad bellum.

Which is why the Pentagon statement seeks to justify the attack on the grounds of preemptive self-defence.

Preemptive Self-Defence

It is obvious that the prohibition of use of force cannot be a blanket one, and the UN Charter expressly recognises a country’s right of self-defence. Article 51 says that no other provision of the Charter shall “impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations.”

A country is entitled to use armed force against another country or even a non-State actor if this is part of its self-defence against an armed attack. The concept of an armed attack is quite broad, and can include attacks on soldiers, military installations, oil platforms or ships on the high seas, factories, or even the nationals of a country.

In this case, although the Pentagon statement references their claims that Soleimani was responsible for the deaths of US personnel, attacks on coalition bases and the recent attack on the US embassy, the US has not argued that its actions were in self-defence against an armed attack which has already happened.

Instead, they seek to justify the killing of the general on the basis of the doctrine of preemptive self-defence, saying:

“At the direction of the President, the US military has taken decisive defensive action to protect US personnel abroad... General Soleimani was actively developing plans to attack American diplomats and service members in Iraq and throughout the region.”

The final paragraph of the statement makes clear that this was done as an act of preemptive self-defence:

This strike was aimed at deterring future Iranian attack plans. The United States will continue to take all necessary action to protect our people and our interests wherever they are around the world.” (emphasis supplied)

These statements could also be taken as an attempt to satisfy the requirements to ensure that this is not a violation of international human rights law, by making a claim that Soleimani posed an “imminent threat” to the lives of US personnel – the test set forth by Agnes Callamard referenced above.

Back in February 2019, the Indian government had sought to use the same concept of preemptive self-defence to justify the Balakot airstrike.

As explained back then, the doctrine of preemptive self-defence states a nation can act in self-defence before an armed attack takes place against them, provided they can show there was a necessity to act which was “instant, overwhelming, leaving no choice of means, and no moment for deliberation”.

This test is derived from the Caroline Affair in 1837, when British forces from Canada attacked a US ship in US territory, because it was being used to support rebels against the British. The British justified the attack as preemptive self-defence, but the US claimed this could only apply when the above test was satisfied.

While there are those who claim Article 51 of the UN Charter doesn’t recognise the right of preemptive self-defence, state practice from the Nuremberg Tribunals to Israel’s air strikes in the Six Days War, and more controversially, the Iraq War, indicate it has become part of customary international law, something which has been acknowledged by many scholars and jurists.

But can the US genuinely claim the right to preemptive self-defence in this case?

Tests to Be Satisfied for Preemptive Self-Defence

To rely on the doctrine of preemptive self-defence, it is essential to show two things.

  1. The use of force was necessary, ie, there was an imminent threat which could not be addressed in any other way.
  2. The force was used in a proportional manner, ie, the response was not excessive.

The second part of the test should not be too difficult for the US to claim in this case, as only eight people are reported to have been killed in the attack – even though it took place next to the Baghdad International Airport.

The claim of an imminent threat, however, seems more difficult to establish. Not that the US hasn’t attempted to do so.

As mentioned earlier, the Pentagon claims that Soleimani and the Quds Force have been responsible for the deaths of hundreds of American and coalition service members and the wounding of thousands more.

Back in April 2019, when Donald Trump and his Secretary of State Mike Pompeo announced they were designating the Quds Force’s parent organisation, the IRGC, as a “foreign terrorist organisation”, Pompeo had claimed that the blood of 603 American soldiers was on Soleimani’s hands.

The US State Department has claimed that Iran is responsible for the deaths of over 600 US troops in Iraq since 2003 – Iran controls several Shia militia groups operating in Iraq, which despite often being allied with the Iraqi government, have at times found themselves at cross-purposes with the US.

The Pentagon statement also takes care to ensure they reference the alleged involvement of Soleimani in the recent attacks on coalition bases (including the one on 27 December which led to the death of a US contractor and allies) as well as the protests at the US Embassy in Baghdad (there were no casualties in the latter).

In fresh comments to CNN on Friday, 3 January, Mike Pompeo affirmed that the killing of Soleimani was in response to “imminent threats to American lives”. Pompeo refused to explain what these threats were, though he did say that they were aimed at American lives in the Middle East, not on American soil. He went on to say:

“It was the time to take this action so that we could disrupt this plot, deter further aggression from Qasem Soleimani and the Iranian regime – as well as to attempt to de-escalate the situation. The risk of doing nothing was enormous. The intelligence community made that assessment, and President Trump acted decisively last night.”

The problem with all of this is that the US is not in a state of armed conflict with Iran. In such circumstances, the killing of an Iranian leader cannot be justified even in terms of preemptive self-defence, especially as there were multiple other options open to the US to address this.

These could have included detention of Soleimani at the airport, a ramping up of sanctions, ultimatums to Iran threatening action against national assets. Remember that Soleimani was hardly some figure in the shadows who moved in secret, like Osama Bin Laden or Abu Bakr al-Bahgdadi; he held an official post and even posted regularly on Instagram.

It should also be noted that the strike was launched on Iraqi soil without informing the Iraqi authorities – who had, in fact, recently condemned US airstrikes on Shia militia targets inside Iraqi territory – possibly meaning that even Iraq could claim that the US had used force against them illegally.

In light of this, it is difficult to see how the actions of the US can be seen as anything but an act of war against Iran, and not one that is justified by the exception of self-defence or more specifically, the doctrine of preemptive self-defence.

What Happens Now?

The unfortunate truth is that even if the “imminent threats” that Soleimani posed are as real as the WMDs in Iraq (ie, non-existent), the US is unlikely to suffer any consequences, thereby exposing the fundamental flaws with the international legal system and why it has come to be ignored by most nations.

If the US is, in fact, claiming a right to preemptive self-defence, then it will need to immediately notify the UN Security Council as per Article 51 of the UN Charter. But even if the rest of the Security Council were to not be satisfied with the US’s claims, no resolution against them would be possible, thanks to the US veto.

A General Assembly resolution would also obviously fail to achieve anything here as it would not be binding, and let’s face it, the Uniting For Peace Resolution process is never going to be activated against the US.

Iran could approach the International Court of Justice (ICJ) but this has not been of much use to countries in the past when seeking to take the US to task, as the US will just refuse jurisdiction and ignore any judgment of the court – just ask Nicaragua.

Nonetheless, it is important for there to be strong analysis and critique of the US position, by other countries, international bodies, international law experts and even academics. Not doing so would allow the actions of the US to become acceptable state practice (adding to their practice of targeted killings of terrorists, which is already a grey area), further eroding the already shaky foundations of international law.

Even if realpolitik dictates that such killings are possible, international law must not be entirely forgotten, so that when we take stock of such matters in the future, we’ve not shot ourselves in the foot.

(The Quint is available on Telegram. For handpicked stories every day, subscribe to us on Telegram)

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