Three weeks ago, the International Criminal Court (ICC) Appeals Chamber announced that on May 6 it would issue its judgment on whether President Omar Al-Bashir of Sudan was entitled to head of state immunity.  At the time, it looked as though this would be one of the biggest decisions of the year – for Al-Bashir, and for the ICC.

Well a lot can happen in three weeks. Bashir has been deposed in Sudan. And the ICC Pre-Trial Chamber’s decision refusing to authorize the Prosecutor’s investigation into crimes in Afghanistan has attracted the bulk of the attention (and considerable criticism) from those who follow the Court.

But there are still good reasons to pay attention to the Appeals Chamber’s judgment next week. While it may not provide new insight into the immunity of heads of state for international crimes, it will likely be the most important decision on the relationship between the ICC and the UN Security Council, giving an insight into how the Court understands the nature of the jurisdiction it exercises when it operates under a Security Council referral. Regardless of what the Appeals Chamber decides, this is likely to impact the way in which the Security Council approaches referrals in the future, especially involving non-state parties.

Factual Background – How Did This Appeal Arise?

Sudan is not a party to the ICC Statute, so the Court’s involvement arises from the UN Security Council’s referral of the situation in Darfur to the ICC some 14 years ago, on March 31, 2005. Following several years of investigation, on March 4, 2009, the Court issued an arrest warrant for President Al-Bashir on charges of war crimes and crimes against humanity. It issued a second warrant, adding genocide charges, on July 12, 2010.  In the intervening years, President Al-Bashir has travelled to a number of ICC States Parties – including Djibouti, Uganda, Chad, Tanzania, Malawi, the Democratic Republic of the Congo, and South Africa – without being arrested.  And in a number of these instances, the Pre-Trial Chamber issued decisions that President Al-Bashir was not entitled to immunity and that the state in question had violated its obligation to cooperate with the Court.

In March 2017, President Al-Bashir once again travelled to an ICC state party, Jordan, to attend the Arab League Summit.  Jordan refused to arrest him, despite formal requests for arrest and surrender from the ICC. Once again, Pre-Trial Chamber II ruled that the state party had failed to comply with its obligation to cooperate with the Court; and referred that non-compliance to the Assembly of States Parties and to the UN Security Council.

This time, however, Jordan chose to elevate the matter by appealing the decision, challenging the conclusions regarding President Al-Bashir’s immunity in light of the ICC Statute, Sudan’s status as a non-party State, and the UN Security Council resolution (as well as other details of the Chamber’s approach to the cooperation regime and the decision to refer non-cooperation to the Assembly of States Parties and UN Security Council). And the Appeals Chamber has not treated this matter lightly: it has accepted eleven submissions from professors of international law as amicus curiae; additional amicus submissions from the African Union and the League of Arab States; and set out 38 separate questions for the participants to address across four days of oral argument in September 2018. This is what the Appeals Chamber will rule on May 6.

Legal Issues – What is This Really About?

350 pages of briefing, 13 amicus briefs, and four days of oral argument indicate the scope and complexity of this appeal. And while there is a lot going on, the core legal issue boils down to whether the head of state of a country which is not party to the ICC Statute (then-President Al-Bashir of Sudan) is immune from the jurisdiction of another state which is an ICC state party (Jordan) when enforcing an arrest warrant issued by the ICC in relation to a situation that the UN Security Council referred to it (Darfur).

This sits at the intersection of a number of thorny questions: the extent of head of state immunity when dealing with international crimes, including genocide; the nature of jurisdiction exercised by a state when its national authorities act on behalf of an international court; and crucially, the application of the ICC Statute to a non-state party when the Court exercises jurisdiction under a referral from the UN Security Council.

Ordinarily, a sitting head of state enjoys absolute immunity (immunity ratione personae) from any exercise of criminal jurisdiction by another state. The ICJ confirmed in the Arrest Warrant case that this immunity exists even in respect of international crimes such as war crimes and crimes against humanity, though noted that this ruling does not necessarily extend to immunity from the jurisdiction of certain international courts.

The ICC Statute is clear that a head of state does not enjoy immunity before the Court (Article 27). But that is a waiver of head of state immunity by states that are party to the ICC Statute. The ICC Statute does not bind non-party states; and they can still assert their state immunity in full. Thus, if the ICC was exercising its ordinary jurisdiction over crimes committed on the territory of a state party, then the President of a non-party state would likely be immune from arrest (even under an ICC arrest warrant) by other nations’ police or judicial authorities. Indeed, the ICC Statute recognizes and seeks to manage the potential conflict between a state party’s obligations to cooperate and obligations not to infringe state immunity of non-parties (Article 98(1)).

The complicating factor here arises from the fact that in the Darfur situation, the ICC is exercising jurisdiction granted to it by the UN Security Council. The resolution by which the Security Council granted the ICC jurisdiction was issued under Chapter VII of the UN Charter (which means this obligation takes precedence over other international obligations). Moreover, the Security Council referral triggered Article 13(b) of the ICC Statute, which allows the Court to exercise jurisdiction over crimes “in accordance with the provisions of this Statute.”

As a result, some argue that this referral places Sudan in the same position as an ICC state party for the purposes of the Darfur investigation, including the absence of immunity for heads of state. Others argue that the Security Council resolution does not go that far – that the ICC Statute (including its abrogation of state immunity) still binds only states parties, and that the language of the resolution (which obliged Sudan to cooperate fully with the Court) is not sufficient to displace core principles of international law such as pacta non tertiis(a treaty only binds its parties), sovereign equality and the absolute immunity of heads of state.

What to Look For in the Appeal Judgment

Will the Appeals Chamber engage with recent developments?

Some of the sting has been taken out of the decision by the fact that Omar Al-Bashir is no longer President of Sudan. The immunity ratione personaeof a head of state attaches to the office; it does not survive to benefit former officials.  But the legal issue of Jordan’s non-cooperation in July 2017 is still live, and the Appeals Chamber has invested heavily in soliciting detailed submissions on this matter. It seems unlikely that it would declare the appeal moot at this stage.

Might the Chamber instead stray into discussion of whether there is any other immunity which might apply?  There is a separate category of functional immunity (immunity ratione materiae) that covers a wider group of officials, current and former, but for a narrower range of “official acts.” Again, this seems unlikely, and any suggestion that senior state officials enjoy functional immunity for international crimes including genocide would be controversial (to say the least).

Will the Appeals Chamber stick to the mainstream legal debate? 

Most international lawyers agree that heads of states not party to the ICC have immunity from national courts enforcing ICC warrants, even for genocide (absent a UN Security Council referral). And most agree that the UN Security Council could override that immunity.  Under the mainstream analysis, the main question on this appeal is how explicit a Security Council resolution must be in order to override that immunity.

That said, “most” is not the same as “all.” There are international lawyers who argue that no head of state is immune from national jurisdiction when the charge is genocide (whether due to its jus cogens nature, or the provisions of the Genocide Convention). Indeed, ICC Judge de Brichambaut took this position in a separate opinion to the Pre-Trial Chamber decision. Others might suggest that a state enforcing an ICC warrant is part of the jurisdiction of an international court, and this falls in the possible exception to immunity foreseen by the ICJ in Arrest Warrants judgment. On the other side, there are those who suggest that the UN Security Council cannot itself abrogate the head of state immunity on behalf of Sudan; that all it can do it oblige Sudan to waive that immunity, and if Sudan does not, then it has violated an obligation it owes to the Security Council – but this would be an issue to be resolved between Sudan and the Council.

I’d think it unlikely that the Appeals Chamber will engage in detail with any of these debates. But if it chooses to do so, then we could be in for a blockbuster decision.

What is the nature of the ICC when acting under UN Security Council referral?

If the Appeals Chamber does not avoid deciding the hard issue because of recent events and sidesteps debates at the margins, the decision will turn on how explicit the UN Security Council must be in order to abrogate head of state immunity when referring a “situation” in a non-party State to the ICC. This may sound dry and technical. It is dry and technical. But it is also important. Because it will give insight into how the Appeals Chamber understands the status and nature of the Court when acting under Security Council referral.

There are two visions of the ICC. One sees it as a pure creature of treaty. Because it is the consensual creation of its states-parties, it can bind only those parties. While the UN Security Council can trigger its jurisdiction over a non-party state, that non-party did not consent to and therefore cannot be bound by any of the other provisions of the Statute.

The other sees two courts in one. A consent-based Court when it exercises jurisdiction that states-parties pooled in and delegated to the Court (i.e. over crimes committed on the territory of, or by nationals of, a state party).  But it also sees the ICC as the standing infrastructure for compulsion-based jurisdiction exercised by the UN Security Council under Chapter VII. A Security Council referral therefore operationalizes the legal framework of the ICC as the default (subject to any modifications in the referral) and applies it to the state in question.

In the first vision, explicit language is required from the Security Council to apply provisions such as the abrogation of immunity for heads of state under Article 27 of the ICC Statute. In the second, explicit language from the Security Council would be required to deviate from such provisions. In sum, the way in which the Appeals Chamber approaches the judgment will tell us much about how it sees the nature of the Court and its relationship with the Security Council.

IMAGE: DEAD SEA, JORDAN- MARCH 29: Sudanese president Omar Hasan Al Bashir attends during the Arab League summit in the Jordanian Dead Sea resort of Sweymah, Jordan, March 29, 2017.  (Photo by Jordan Pix/ Getty Images)