As Ryan noted last week, the United Kingdom’s High Court ruled in Serdar Mohammed v. Ministry of Defense that the United Kingdom’s 110-day detention of a suspected Taliban commander and the detention of three other men for around 290 days in Afghanistan were unlawful.

The decision addressed a wide range of complex legal issues. In this post we’ll focus on the Court’s conclusions about the relationship between international humanitarian law (IHL) and the United Kingdom’s obligations under the European Convention of Human Rights.

The Court’s decision, which remains subject to appeal, concluded that international human rights law (IHRL) plays a central role in detention during non-international armed conflict (NIAC).

The relationship between IHL and IHRL is a hot topic of debate amongst international lawyers and advocates. International, regional, and several domestic courts, as well as UN quasi-judicial human rights bodies largely agree that IHRL and IHL are co-applicable in times of armed conflict, while the United States and others insist otherwise. What remains largely unresolved is how precisely IHL and IHRL interact as co-applicable bodies of law. This includes the unresolved issue of how the two bodies of law operate in the detention of individuals for security or intelligence gathering purposes during a NIAC.

The U.K. Court’s decision largely re-affirmed what many human rights groups working on detention issues in Afghanistan have been saying for quite some time: IHL provides no legal authority for a State in a NIAC to detain or intern an individual, and IHRL and Afghan domestic law governs such detentions.

Critically, the Court rejected the Ministry of Defence’s (MOD) argument that IHL contained an “implicit power to detain.” The Court noted that notwithstanding the conclusion of ICRC and others that Common Article 3 (CA 3) and Additional Protocol II (AP II) “contemplate” internment or non-judicial detention as a measure that can be taken in a NIAC, these provisions do not themselves provide the legal authority to detain.

The MOD also argued that its legal basis to detain emanated from customary IHL, citing the principles and guidelines developed in the Copenhagen Process on the Handling of Detainees on International Military Operations (see here and here). The Court was not persuaded, noting that principle 16 and its commentary said that the principles and guidelines do not affect “the applicability of international law to international military operations” and “were not written as a restatement of customary international law,” but instead “reflect generally accepted standards.”

Though this gap in IHL may seem extraordinary at first, it is understandable. When states drafted CA 3, and later AP II, they were not comfortable with international law dictating their domestic detention powers and procedures. Particularly because NIACs were traditionally envisaged to consist of armed conflicts between a state and domestic armed groups (or between two or more domestic armed groups) it was left to the states, so it was argued, to determine how to manage internal affairs.  The Court also noted that if IHL granted a state a legal basis to detain in NIACs, this “would have meant authorising detention by dissident and rebel armed groups. That would be anathema to most states.”

It is largely for these reasons that the IHL applicable to NIAC provides only basic humane treatment standards for internees/detainees, no procedural guarantees for internment, and contains only the implied assumption that states may, through their domestic law, deprive people of their liberty for security reasons.

The Court also assessed MOD’s claim that IHL either “displaces or disqualifies” Article 5 of the European Convention on Human Rights in times of armed conflict under the principle of lex specialis.  The Court examined various interpretations of this principle but ultimately concluded the principle was of no use.  There was, the Court determined, no reason for IHL to displace or disqualify Article 5 under the principle of lex specilias because IHL contained no legal basis or procedural rules for NIAC detention in the first place. As a result, the Court ruled that the United Kingdom had to comply with its Article 5 obligations.

While this might create heartburn for IHL’ers who feel threatened by the “encroachment” of IHRL into the law of armed conflict, the Court’s conclusion is largely consistent with how IHL was intended to be applied in NIACs.

The drafters of IHL treaty law purposefully permitted a state’s domestic law to determine the appropriate detention and internment powers in NIAC. While in the past this may have meant that a state had a free hand to detain individuals as it wished, times have changed and today states’ domestic detention regimes are also subject to the requirements and procedural guarantees of IHRL.

While states may have the power to detain individuals on security grounds during NIAC, the Court makes clear that the source and scope of that authority is generally governed by domestic law and IHRL.

Relatedly, the Court also assessed the role of derogations in determining the applicability of IHRL in a NIAC. More specifically, the Court considered whether the application of the lex specialis principle would enable the United Kingdom to engage in law of war detention without derogating from the Convention. (Ryan’s post here, for example, explains how states could derogate from IHRL and adopt a lawful internment regime).

The Court acknowledged that it was not necessary to address this issue since it had determined there was no IHL/IHRL conflict in the matter it was adjudicating, but nonetheless, the Court said that, “at least arguably,” lex specialis would not abrogate the need for derogation if a conflict were to arise:

Even in a case where such a conflict of obligations occurs, the only way in which the European Court or a national court required to apply Convention rights can hold that IHL prevails over Article 5 is by applying the provisions for derogation contained in the Convention itself, and not by invoking the principle of lex specialis.

The Court reasoned,

in circumstances where the Convention itself defines the conditions in which and the extent to which derogation from its obligations is permitted, and makes specific provision for derogation in time of war, it is difficult to see that there is any room for the lex specialis principle to operate as a basis for disapplying the Convention when it conflicts with IHL.

The final issue we want to draw attention to is the Court’s view on the relationship between IHRL and domestic law in the context of NIACs.

Too often, states engaged in NIACs abroad do not give sufficient deference to the domestic legal obligations and sovereignty of the host state.  Years of bitter, public dispute over U.S. detentions in Afghanistan have illustrated that this can lead to serious political and operational consequences.

The Court, cautiously, took the view that domestic law may indeed have a strong impact on the legality of NIAC detention operations conducted by foreign forces:

It seems to me to be an open question whether in a case where international law is relied on as providing a legal basis for detention, it is also necessary for the detention to comply with the applicable national law.  Arguably, it is – at least in circumstances where the detaining authority (i.e. in this case the UK government) is operating on the territory of an independent sovereign state at the invitation or with the consent of the government of that state.

Because, however, no parties to the litigation raised this issue, the Court proceeded “on the assumption that it is sufficient in order to establish the lawfulness of SM’s detention to show that there was a legal basis for it under international law.”

The Court’s decision articulated a historically-grounded, compelling view on the relationship between IHRL and IHL in NIAC. While the principle of lex specialis is often thrown around as the cure-all to resolving the tensions between IHL and IHRL, the Court highlighted the limits of the lex specialis principle, and when and how it should be applied.

In addition, the Court’s decision brought legal clarity to a complicated and unavoidable reality in today’s NIACs. When a state is party to a NIAC abroad, as is the case in Afghanistan, this strains IHL’s historical expectation that the territorial state’s domestic law would govern detentions.

What the Court’s decision highlighted, is that the answers to the challenges that this issue raises do not lie in provisions of IHL but instead within IHRL and the host state’s domestic law. As noted above, this approach may be not only legally correct, but it can also reduce of the kind of political backlash that the United Kingdom (and the United States) have faced as a result of asserting a detention power that many Afghans see as violating Afghan law and sovereignty.

For additional analysis of the Court’s decision, we recommend Marko Milanovic’s piece over at EJIL Talk.