Citizenship · Year 10

Active learning ideas

International Law: Treaties & Custom

Active learning helps students grasp the abstract nature of international law by making its sources tangible. Debates, simulations, and case studies transform treaty negotiations and customary practices from distant concepts into concrete, interactive experiences that build retention and critical thinking.

• National Curriculum Attainment Targets
• GCSE: Citizenship - International Law and Treaties

• 30–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Document Mystery
• 40 min · Pairs

Debate Pairs: Treaty vs Customary Law

Pair students to prepare arguments: one side defends treaties as clearer and more reliable, the other praises customary law's flexibility. Each pair presents for 3 minutes, then switches sides. Class votes on strongest points and discusses real examples like the Geneva Conventions.

Explain the difference between international treaties and customary international law.

Facilitation Tip

During the Debate Pairs activity, circulate to ensure each pair has clear roles and pre-selected cases to compare, preventing vague or unfocused discussions.

What to look for

Pose the following question to small groups: 'Imagine a new global crisis emerges requiring immediate international cooperation. Would it be more effective to create a new treaty or rely on existing customary international law? Justify your answer with specific examples of challenges and benefits for each.' Allow groups 10 minutes to discuss before sharing key points.

• Analyze
• Evaluate
• Self-Management
• Decision-Making

Activity 02

• Simulation Game
• 50 min · Small Groups

Simulation Game: Mock UN Treaty Negotiation

Assign roles as state representatives with conflicting interests, such as environmental vs economic priorities. Groups draft a short treaty over 20 minutes, then present for ratification vote. Debrief on ratification challenges and sovereignty issues.

Analyze how international law is created and enforced.

Facilitation Tip

For the Mock UN Treaty Negotiation, provide a structured negotiation guide with clear time limits and topic parameters to keep the simulation focused and productive.

What to look for

On a slip of paper, ask students to: 1. Define 'treaty' in their own words. 2. Provide one example of customary international law. 3. State one reason why enforcing international law can be difficult for states.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Activity 03

• Document Mystery
• 45 min · Small Groups

Case Study Carousel: Enforcement Examples

Set up stations with cases like the ICJ Nicaragua ruling or UN sanctions on North Korea. Small groups rotate, noting creation, enforcement attempts, and sovereignty hurdles. Each group shares one insight in a whole-class summary.

Assess the challenges of state sovereignty in the application of international law.

Facilitation Tip

In the Case Study Carousel, assign small groups to specific stations and rotate roles so everyone engages with each enforcement example, avoiding passive observation.

What to look for

Present students with two scenarios: Scenario A describes a formal agreement signed by 50 countries, while Scenario B describes a practice followed by most countries for centuries, such as diplomatic immunity. Ask students to identify which is an example of a treaty and which is customary international law, and to briefly explain their reasoning for each.

• Analyze
• Evaluate
• Self-Management
• Decision-Making

Activity 04

• Document Mystery
• 30 min · Individual

Timeline Individual: Evolution of a Custom

Students research one custom, such as maritime boundaries, and create a timeline of practices leading to legal status. Include key treaties that codified it. Share digitally or on posters for class gallery walk.

Explain the difference between international treaties and customary international law.

Facilitation Tip

For the Timeline Individual activity, supply a mix of primary and secondary sources to help students trace the evolution of customs accurately and efficiently.

What to look for

Pose the following question to small groups: 'Imagine a new global crisis emerges requiring immediate international cooperation. Would it be more effective to create a new treaty or rely on existing customary international law? Justify your answer with specific examples of challenges and benefits for each.' Allow groups 10 minutes to discuss before sharing key points.

• Analyze
• Evaluate
• Self-Management
• Decision-Making

A few notes on teaching this unit

Teach this topic by balancing theory with lived experience. Start with a brief overview, then immerse students in activities that require them to apply concepts. Research shows that simulations and case studies build empathy and understanding of sovereignty’s role, while debates sharpen analytical skills. Avoid overloading with legal jargon; focus on the purpose and impact of each source instead.

Successful learning looks like students distinguishing between treaties and customs in real time, articulating why enforcement varies, and connecting historical examples to current global issues. They should confidently explain how these sources shape state behavior and international cooperation.

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Watch Out for These Misconceptions

• During Debate Pairs, watch for students assuming all international law comes from treaties.

  Use the debate format to have pairs compare a treaty-based agreement, like the Paris Climate Agreement, with a customary practice, such as the prohibition of slavery. Ask them to identify how each source binds states differently and why customary law persists even without formal ratification.

• During Mock UN Treaty Negotiation, watch for students expecting international law to work like domestic law with centralized enforcement.

  During the simulation, emphasize state consent and voluntary compliance by including a clause in the negotiation guide that allows states to opt out of enforcement mechanisms. Debrief by asking groups to reflect on why enforcement is often weak or inconsistent in real negotiations.

• During Case Study Carousel, watch for students believing treaties automatically bind all countries.

  Use the carousel stations to present examples of treaties with varying ratification rates, such as the Convention on the Rights of the Child. Ask students to note which countries have not ratified each treaty and discuss how customary law might still apply to those cases.

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Methods used in this brief

• Document Mystery
• Simulation Game