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Can the US Justify its Position as a Right to Self-Defense and can President Trump be Prosecuted for the Crime of Aggression?
Can the US Justify its Position as a Right to Self-Defense and can President Trump be Prosecuted for the Crime of Aggression?

One of the underlying rationales of the UN Charter, as highlighted in its preamble, is to ‘to save succeeding generations from the scourge of war, which twice in our lifetime has brought untold sorrow to mankind’. Any obvious statement in regards to Iran’s immediate reaction would be immature; however, it can be reasonably established that the assassination of General Qasem Soleimani awaits untold sorrows that may have grave repercussions short of the World Wars.

The assassination of Iran’s top military general by President Donald Trump’s authorized drone strike on Thursday night raises a critical global concern. Its political implications may be severe enough to change the course of history.  The important question to address would be the legal justifications for such an act. 

The Pentagon and the White House were clear in their statement: the strike was directed by President Trump as a decisive defensive measure to ‘protect’ U.S personnel. Their statement seems to engage the international law justification of self-defense which is the only exception to the prohibition on the use of force under the UN Charter. Otherwise, both the customary international law  and Article 2(4) of the UN Charter prohibits the use of force (see Case Concerning Military and Paramilitary Activities In and Against Nicaragua (ICJ) 1986, para 74).

Before I deal with the question of self-defense, the matter requires a quick look into Iraq’s sovereignty and legal obligations to General Soleimani. This topic itself requires another article; however, a brief discussion over here would be suffice to provide an overview. A limited number of state representatives are so closely tied to the sovereignty of the state that they enjoy particularly extensive protection. The major legal protection offered is diplomatic immunity. General Soleimani was a representative of Iran. As a second most powerful figure in Iran, General Soleimani attracted a greater diplomatic value. In other words, his official status represented the sovereignty of Iran.

Therefore, depending on the details of his presence in Iraq, he was entitled to diplomatic immunity guaranteed by the customary international law and the 1961 Vienna Convention on Diplomatic Relations. Iraq’s failure to protect General Soleimani will be a manifest breach of the laws of diplomatic immunity. The reaction of Iraqi official suggests that they were unaware of the assassination. Therefore, it raises the legal question of the breach of Iraqi sovereignty. If the assassination were carried without Iraq’s permission, the US would be liable for the breach of Iraqi sovereignty and the diplomatic immunity of its guests. However, a manifest right to self-defence may change the nature of such legal arguments.

The Right to Self Defense

The right to self-defense is an inherent right under customary international law and article 51 of the UN Charter.  There has been extensive controversy as to the precise extent of the right to self-defence. Before 2001, the right to self-defense was only available against the use of force of another state. However, after the rise of terrorism, States can now rely on the right to self-defense against non-state actors.

General Soleimani was a military General representing the Islamic Republic of Iran. Per the secondary rules of International Law Commission’s Articles on Responsibility of States for Internationally Wrongful Acts, conducts of any state organ or official entities are attributed as an act of the State(see Articles: 4, 5,6 & 7). Therefore, he cannot be regarded as a non-state actor. To rely on the self-defense for its use of force against General Soleimani, the President Trump administration has to fulfill the criteria’s essential for the right to self-defense.

Firstly, the right to self-defense is triggered by ‘an armed attack’; secondly, customary international law requires that self-defense would warrant only measures which are proportionate to the armed attack and necessary to respond to it (see Nicaragua case 1986 para 94; and The Caroline case 1837).

Thus, the US has to connect any armed attack to Iran. The armed attack must be of certain intensity to trigger a right to self-defense and not all uses of force prescribed by article 2(4) qualify. Case law suggests that only acts producing or likely to produce very serious consequences, such as territorial invasions, human fatalities or massive destruction of property will suffice to constitute an armed attack that triggers a right to self-defense. (see Oil Platforms case (Iran v USA ) ICJ 2003; the 1996 Advisory Opinion on the Use of Nuclear Weapons; and Nicaragua Case). Hence, while a state that fears a potential attack from another state may make its own military preparations in anticipation of the attack and bring the matter to the attention of the Security Council, it may not resort to any measures of self-defense until the attack takes place. There is the exception of anticipatory self-defense which is only available when the threat is imminent, unlikely to apply here. The acts committed by General Soliemani or Iran can either not be attributed directly to Iran or cannot be categorized as armed attacks.

 President Trump, in his tweets, attributes the loss of thousands of Americans to General Soleimani. Although a bold statement, there is little evidence to prove. Since the US withdrawal from the Iran Nuclear Deal in May 2018, the US and its allies have contributed several armed attacks to Iran. The recent ones include 14 September 2019 attacks on Saudi Arabia oil facilities which the Houthi Movement took responsibility as a retaliation for Saudi airstrikes on Yemen. The UN was unable to confirm Iran’s involvement. On the other hand, there was also no evidence of Iran’s involvement in 19th May 2019 rocket attack near the US embassy in Baghdad in which no one was harmed. The only attributed act that harmed US property was the 20th June shooting down of US Drone which Iran claims was flying over Iranian air space; the shooting down of US Drone cannot constitute an armed attack if it were flying over Iran’s air space. On the contrary, Iraq is responsible for the safety of the US embassy in light of recent protest. It was well established by ICJ in Tehran Hostages case, that States are responsible for the diplomatic protection of diplomats on its premises from its citizens (see Tehran Hostage case (USA v Iran) ICJ 1981, para 67).

Even if a strong argument for an armed attack attributing to Iran is made, the customary international law requirements of proportionality and necessity set a high threshold undermining the US claim of right to self-defense. The necessity requirement requires that the armed attack occurred or is reasonably believed to be imminent, requiring the essential response proposed. Similarly, the response has to be proportionate; proportionality also requires the consideration of the type of weaponry to be used. It is unclear what event the US can use as a necessity but the killing of General Soleimani cannot be held as a proportionate response.

Iran’s legal Options: Can Trump be prosecuted for the crime of aggression?

Iran has the conventional right to self-defense and can use force. There is also a peaceful remedy that Iran can avail through the routes of the International Court of Justice (ICJ) and the International Criminal Court (ICC).  It can demand reparation against the US in the ICJ. On the other hand, Iran may request the ICC to prosecute President Donald Trump for the crime of aggression. Aggression is a crime under the Rome statute which by its character, gravity and scale, constitutes a manifest violation of the Charter of the UN (see Rome Statute Article 8bis(2)). The crime of aggression is limited to the absolute leadership of a State. Article 13 of the Rome Statute gives the ICC leniency on establishing its jurisdiction. ICC can establish its jurisdiction, if the crime is referred to the Prosecutor by the State Party to the Rome Statute; By the Security Council; or if the Prosecutor initiates an investigation in respect of such crime. Neither the US nor Iran and Iraq are parties to the Rome Statute, the statute establishing ICC; therefore, ICC can only prosecute President Trump if the Security Council authorizes or the Prosecutor arbitrarily initiates investigation. A prominent example available to us is that of Sudan’s former President Omar Al Bashir, who was investigated by the ICC for war crimes as a sitting President at the request of the Security Council. Nevertheless, Iran’s success in prosecuting President Trump at ICC is very unlikely, but the doors of ICJ are open so is the right to use force.


Israr Khan a Legal Adviser at the Citizens Advice Bureau. He is also studying Law at the University of Aberdeen, UK.

Suggested citation: Israr Khan, Can the US Justify its Position as a Right to Self-Defense and can President Trump be Prosecuted for the Crime of Aggression?, JURIST – Student Commentary, January 13, 2020, 


This article was prepared for publication by Brittney Zeller, Deputy Managing Editor for JURIST Commentary. Please direct any questions or comments to her at

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