Legal Definitions - complementarity

The principle of complementarity defines the working relationship between the International Criminal Court (ICC) and the national justice systems of individual countries. It is a foundational concept ensuring that countries retain the primary responsibility for investigating and prosecuting the most serious international crimes, such as genocide, war crimes, and crimes against humanity, committed within their borders or by their citizens.

Under complementarity, the ICC acts as a court of last resort. It will only step in and exercise its jurisdiction if a country is genuinely unwilling or unable to carry out these investigations and prosecutions itself. This means:

• If a country is unwilling, it suggests that its justice system is not genuinely seeking justice. This might involve conducting sham investigations, attempting to shield perpetrators from accountability, or deliberately delaying proceedings.
• If a country is unable, it means its justice system lacks the capacity, resources, or functioning institutions to conduct a proper investigation or trial. This could be due to a collapsed government, ongoing conflict, or a complete breakdown of the rule of law.

This principle respects national sovereignty while also providing a crucial safeguard against impunity for the gravest crimes when national systems fail to deliver justice.

Here are some examples illustrating how complementarity works:

• Example 1: A Robust National Prosecution

  Following a period of internal conflict, Country X establishes a special tribunal staffed by independent judges and prosecutors. This tribunal thoroughly investigates allegations of war crimes committed by both government forces and rebel groups. Several high-ranking military officers and rebel commanders are indicted, tried, and convicted in fair proceedings that meet international standards.

  How it illustrates complementarity: In this scenario, Country X's national justice system has genuinely fulfilled its primary responsibility to investigate and prosecute international crimes. The ICC would not intervene, respecting the country's sovereign right and ability to deliver justice effectively.

• Example 2: A Sham Investigation

  After widespread reports of crimes against humanity committed by security forces, Country Y initiates an investigation. However, the investigation is widely criticized for its lack of independence, with key witnesses intimidated and crucial evidence suppressed. The few low-ranking officers charged are given lenient sentences, while high-ranking officials implicated in the crimes are never questioned.

  How it illustrates complementarity: Here, Country Y's justice system appears to be "unwilling" to genuinely prosecute. The investigation is perceived as a cover-up designed to shield perpetrators rather than seek true accountability. This situation would likely trigger the ICC's secondary jurisdiction, allowing it to consider taking over the case because the national system is not acting in good faith.

• Example 3: A Collapsed Judicial System

  Due to a prolonged civil war and the complete breakdown of state institutions, Country Z no longer has a functioning police force, courts, or legal infrastructure. Mass atrocities are ongoing, but there is no capacity whatsoever within the country to investigate crimes, arrest suspects, or conduct trials.

  How it illustrates complementarity: This illustrates a situation where Country Z is clearly "unable" to prosecute international crimes. With no functioning justice system, it is impossible for the country to fulfill its primary responsibility. In such circumstances, the ICC would be justified in exercising its jurisdiction to ensure that justice is pursued for the victims.