The Duty to Investigate in Situations of Armed Conflict

Floris Tan, PhD (2022) is a legal officer with the Netherlands Ministry of Foreign Affairs. He obtained his PhD from Leiden University. His publications are in the field of human rights law and, beyond the topic of his PhD, relate to the prohibition of limitation of rights for ulterior purposes.

Acknowledgements


List of Figures


Abbreviations


Table of Cases


Table of Instruments


1 Introduction

1 Investigating Incidents in Armed Conflict Situations

 1.1 The Role of Investigations during Armed Conflicts


 1.2 Investigations during Armed Conflicts: A Search for Clarity




2 Central Research Questions

 2.1 Questions Guiding the Enquiry


 2.2 Breaking Down the Research Question: Relevant Concepts and Terminology




3 Selecting Research Methods

 3.1 The Doctrinal Legal Method and the Question What the Law Is


 3.2 Tailoring the Method, and Structuring the Enquiry




Part 1

International Humanitarian Law

2 Introduction to the ihl System

1 Introduction


2 The Aims, Purposes, and Main Sources of ihl


3 The Principles of ihl


4 ihl’s Scope of Application

 4.1 Introduction


 4.2 ihl’s Material Scope of Application


 4.3 ihl’s Personal Scope of Application


 4.4 ihl’s Temporal and Geographic Scope of Application




5 ihl’s Implementation, Supervision, and Enforcement System

 5.1 From the State Level …


 5.2 … to the International …


 5.3 … Back to the State


 5.4 Résumé




6 Conclusion




3 The Duty to Investigate Violations of ihl

1 Introduction


2 The ihl System’s Implication of Investigations

 2.1 The System of Self-enforcement and the Duty to Ensure Respect for ihl


 2.2 Rationales for Investigative Obligations under ihl


 2.3 Résumé




3 Scope of Application and Sources of Investigative Obligations

 3.1 Introduction


 3.2 Serious Violations of ihl: War Crimes


 3.3 Other ihl Violations


 3.4 Investigations in Non-international Armed Conflicts


 3.5 Résumé




4 Substance of the Obligation: Investigative Standards

 4.1 Introduction


 4.2 The Nature and Purpose of the Investigation: Criminal or Administrative


 4.3 Standards for Investigations Into Serious ihl Violations (War Crimes)


 4.4 Standards for Investigations Into Simple ihl Violations


 4.5 Résumé




5 Conclusion: The Duty to Investigate ihl Violations




Part 2

International Human Rights Law

4 Introduction to the ihrl System

1 Introduction


2 The Aims, Purposes, and Main Sources of ihrl


3 The Nature of Human Rights Obligations

 3.1 Introduction


 3.2 Rights and Obligations


 3.3 Positive and Procedural Obligations




4 ihrl’s Scope of Application

 4.1 Introduction


 4.2 ihrl’s Material Scope of Application


 4.3 ihrl’s Personal Scope of Application


 4.4 ihrl’s Temporal Scope of Application


 4.5 ihrl’s Geographic Scope of Application


 4.6 ihrl’s Applicability during Armed Conflict and Occupation




5 ihrl’s Implementation, Supervision, and Enforcement Mechanisms


6 Conclusion




5 The Duty to Investigate under the Global Human Rights Systems

1 Introduction


2 Explicit Duties of Investigation in Global Human Rights Treaties and the Sword-Function of Human Rights Law


3 Legal Basis and Rationale for the Duty to Investigate under the iccpr

 3.1 Introduction


 3.2 Legal Basis for the Duty to Investigate under the iccpr


 3.3 Rationale of the Duty to Investigate under the iccpr




4 Scope of Application of the Duty to Investigate under the iccpr

 4.1 Introduction


 4.2 The Material Scope of Application and the Investigative Trigger


 4.3 The Personal Scope of Application


 4.4 The Temporal Scope of Application


 4.5 The Geographic Scope of Application




5 Substance of the Duty to Investigate: Investigative Standards under the iccpr

 5.1 Introduction


 5.2 A Due Diligence Obligation


 5.3 Investigative Standards


 5.4 Résumé




6 Applicability and Flexibility in Conflict Situations, and the Role of ihl

 6.1 Introduction


 6.2 The (Non-)Derogability of the Duty to Investigate


 6.3 Applicability during Armed Conflict and Interaction with ihl


 6.4 Investigations into Violations Committed during Armed Conflict




7 Conclusion




6 The Duty to Investigate under the Inter-American System of Human Rights Protection

1 Introduction


2 The Inter-American Context

 2.1 Endemic Human Rights Abuses and the Dawn of the Fight against Impunity


 2.2 The Prevalence of Civil Wars and the Interaction with International Humanitarian Law




3 Legal Basis, Rationale and Consequences of the Duty to Investigate

 3.1 Introduction


 3.2 Legal Basis for the Duty to Investigate under the achr


 3.3 Rationale of the Duty to Investigate under the achr


 3.4 Legal Consequences on the International and National Levels




4 Scope of Application of the Duty to Investigate

 4.1 Introduction


 4.2 The Material Scope of Application and the Investigative Trigger


 4.3 The Personal Scope of Application


 4.4 The Temporal Scope of Application


 4.5 The Geographic Scope of Application


 4.6 Résumé




5 Substance of the Duty to Investigate: Investigative Standards

 5.1 Introduction


 5.2 A Due Diligence Obligation


 5.3 Investigative Standards




6 Applicability and Flexibility in Conflict Situations, and the Role of ihl

 6.1 Introduction


 6.2 The (Non-)Derogability of the Duty to Investigate


 6.3 International Humanitarian Law in the Inter-American Human Rights System


 6.4 Investigations Into Violations Committed during Armed Conflict




7 Conclusion




7 The Duty to Investigate under the European System of Human Rights Protection

1 Introduction


2 The European Context


3 Legal Basis and Rationale of the Duty to Investigate under the echr

 3.1 Introduction


 3.2 Legal Basis for the Duty to Investigate under the echr


 3.3 Rationale of the Duty to Investigate under the echr




4 Scope of Application of the Duty to Investigate under the echr

 4.1 Introduction


 4.2 The Material Scope of Application and the Investigative Trigger


 4.3 Personal Scope of Application


 4.4 Temporal Scope of Application


 4.5 Geographic Scope of Application


 4.6 Résumé




5 Substance of the Duty to Investigate: Investigative Standards under the echr

 5.1 Introduction


 5.2 An Obligation of Means, Not of Result


 5.3 Investigative Standards


 5.4 Résumé




6 Applicability and Flexibility in Conflict Situations, and the Role of ihl

 6.1 Introduction


 6.2 The (Non-)Derogability of the Duty to Investigate


 6.3 Applicability during Armed Conflict and Interaction with ihl


 6.4 Investigations Into Violations Committed during Armed Conflict




7 Conclusion




8 Duties of Investigation under International Human Rights Law – Conclusions

1 Duties of Investigation under the International Law of Human Rights

 1.1 Bringing the Human Rights Research Together


 1.2 The Sword-Function of ihrl and Explicit Investigative Obligations


 1.3 The Why of Investigations: Rationale, Legal Basis, and Place within the System


 1.4 The When of Investigations: Scope of Application and Knowledge Triggering the Duty to Investigate


 1.5 The How of Investigations: Investigative Standards


 1.6 The Duty to Investigate and Armed Conflict


 1.7 Conclusion





Part 3

Interplay

9 The Interplay between ihl and ihrl – A Roadmap

1 Introduction


2 Context and Background: The Nature of International Law

 2.1 A Polycentric Legal System


 2.2 Of Trees and Octopuses: Articulating the Nature of the International Legal System




3 From Fragmentation to Interplay: Concurrent Application of ihl and ihrl

 3.1 ihl and ihrl against the Background of Fragmentation


 3.2 The Fear of Co-existing and Co-applying: A Polarised Debate


 3.3 Contemporary Controversies




4 Developing an Interplay Methodology

 4.1 Introduction


 4.2 Interaction of Norms in the International Legal System


 4.3 Articulating a Methodology for Interplay: A Step-By-Step Approach




5 Articulating Situations of Interplay in Normative Terms

 5.1 Conflicting Conceptions of Conflict


 5.2 A Typology of Normative Overlap: Conflict, Convergence and Competition


 5.3 Résumé: Refining the Methodology for Interplay




6 Solving Situations of Interplay

 6.1 Introduction


 6.2 The Limited Role of Conflict Clauses and Derogations


 6.3 Conflicting Norms


 6.4 Converging Norms


 6.5 Competing Norms




7 Conclusion




10 The Duty to Investigate under the Interplay of ihl and ihrl

1 Putting together the Pieces of the Puzzle: A Roadmap


2 The Aims of Investigations under ihl and ihrl


3 Scope and Triggers of the Duty to Investigate under Interplay

 3.1 Introduction


 3.2 The Relationship between the Duty to Investigate and Substantive Issues of Interplay


 3.3 Convergence in the Scope of Investigative Duties


 3.4 Divergence in the Scope of Investigative Duties


 3.5 Information Triggering the Duty to Investigate


 3.6 Résumé




4 Procedural Standards of the Duty to Investigate under Interplay

 4.1 Introduction


 4.2 Convergence in the Investigative Standards


 4.3 Divergence in the Investigative Standards


 4.4 Résumé




5 Conclusion




11 Drawing Conclusions

1 Answering the Research Question


2 Overarching Conclusions on the Duty to Investigate under ihl

 2.1 ihl’s System of Self-Enforcement


 2.2 The Scope of the Duty to Investigate under ihl


 2.3 Knowledge Triggering the Duty to Investigate


 2.4 Investigative Standards and the Question How States Must Conduct an Investigation




3 Overarching Conclusions on the Duty to Investigate during Armed Conflict under ihrl

 3.1 Legal Basis of Investigative Obligations


 3.2 Rationale and Place of Investigations within the ihrl Framework


 3.3 The Scope and Contents of Investigative Obligations under ihrl


 3.4 The Scope and Contents of the Duty of Investigative Obligations under ihrl during Armed Conflict




4 Overarching Conclusions on the Interplay between ihl and ihrl


5 Duties of Investigation under the Interplay of ihl and ihrl

 5.1 Rationale


 5.2 Scope of Application


 5.3 Knowledge Triggering the Duty to Investigate


 5.4 The Applicable Investigative Standards under Interplay




6 Investigations and Armed Conflict: A Final Reflection




Bibliography


Curriculum Vitae


Index