Edexcel A-Level Politics 9PL0 · Paper 3 Global · Content area 6 of 6

6. Comparative theories

6.1 realism · 6.2 liberalism · 6.3 divisions between them · 6.4 the anarchical society · 6.5 explaining developments since 2000.

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Progress

6.1 Main ideas of realism Done

Essential States, anarchy, the inevitability of war and the security dilemma.

The specification

6.1Main ideas of realism

Key terminology - tick the terms you can define: Realism International anarchy Security dilemma Balance of power

States as key actors in global politics and the balance of power (state sovereignty). I can do this

International anarchy and its implications. I can do this

Inevitability of war. I can do this

The security dilemma. I can do this

Wording above is the Pearson specification, unchanged. Tick a line only when you could answer a question on it without notes.

Past questions - how it has been examined

Directly: 2025 Q2 (realist vs liberalist views of the inevitability of war); 2020 Q2 (security dilemma vs complex interdependence).
Partially: 2022 Q2 (human nature and power); 2023 Q2 (explaining developments since 2000).

What examiners reward and penalise

Stronger: link the concepts (anarchy leads to self-help leads to the security dilemma).
Weaker: list realist ideas without connecting them.
Misconception: treating realism as simply 'war-loving' rather than pessimistic about order.

One way to get high marks

Credited: anarchy makes conflict structurally likely.
Evidence: Ukraine 2022; US-China rivalry; NATO expansion and the security dilemma.
Level 5: applies realism to recent events, not just theory.

The 12-mark Analyse question (Q2). Compulsory, and always on realism and liberalism. Marked on AO1 and AO2 only, 6 marks each. There is no AO3, so no introduction, no conclusion and no overall judgement: write three short paragraphs, each drawing a direct difference or similarity between the two theories. Answers that connect the theories to the core ideas from Paper 1 (for example liberalism as an ideology, or conservative views of human nature) reach the top levels; answers with no such links are capped at Level 3.

In the 30-mark essays. Realism and liberalism are also your sharpest AO2 tools in Section C: using them to frame an argument (a realist would expect this, a liberal would reply that) is what "perceptive analysis" looks like to an examiner.

Full official mark schemes for every Paper 3 Global question, year by year: open the Paper 3 Global mark scheme viewer.

Arguments and counter-arguments

Does realism best explain global politics?

Yes

Point. Realists argue that international anarchy drives the way states behave. Explanation. Because there is no higher authority to protect them, states must rely on self-help. This means war can always return. Example. Ukraine 2022 and the US-Israel-Iran war (2026) both show major wars breaking out in an anarchic system. Evaluation. However, this view underplays the large amount of cooperation that still happens between states.
Point. Power politics is still at the centre of global affairs. Explanation. States continue to build power and balance against rivals, just as realists predict. Example. The growing rivalry between the US and China is a clear case of balance-of-power behaviour. Evaluation. However, this reading ignores the interdependence that ties states together.

No

Point. States do cooperate, often and successfully. Explanation. International institutions soften the effects of anarchy by giving states rules and forums to work through. Example. The EU and the UN are both examples of lasting cooperation between states. Evaluation. This is the liberal reading, and it captures something realism leaves out.
Point. Economic interdependence restrains states from going to war. Explanation. When states trade heavily with each other, war becomes extremely costly. That gives them a strong reason to avoid it. Example. Trade between the US and China is the standout example. Evaluation. Interdependence did not stop the war in Ukraine, however, so it is no guarantee of peace.

Best judgement. Realism explains conflict and great-power rivalry well, especially since 2000, but it underplays the cooperation and interdependence that liberalism captures, so each theory explains part of the picture.

Using it in essays

12-mark (Q2): realist vs liberal on war, the security dilemma, human nature.
Topic sentence: "For realists, anarchy makes self-help and conflict structural rather than accidental."

Practise this on PantherComparative theories walkthrough Comparative theories notes Theories flashcards

Wider context

Helpful context

NATO expansion and Russia is the textbook security-dilemma case: a defensive move read as a threat.

Examination priority

Essential Realism is half of every theory (Q2) question.

Named realists: a sentence or two is enough

The spec does not name realist thinkers, but board sample answers use them, so know two or three in one sentence each.

Waltz	Structural realism: anarchy, not human nature, forces states into self-help, and a bipolar world is the most stable (his reading of the Cold War). Use for polarity questions.
Mearsheimer	Offensive realism: great powers seek to maximise power, so rivalry never ends. He argued NATO expansion provoked the Russia-Ukraine war. Use for Ukraine 2022 and great-power competition.
Morgenthau	Classical realism: politics is governed by self-interest rooted in human nature, so states pursue power defined as the national interest.

6.2 Main ideas of liberalism Done

Essential Optimism, interdependence, institutions and cooperation.

The specification

6.2Main ideas of liberalism

Key terminology - tick the terms you can define: Liberalism Complex interdependence Global governance

The significance of morality and optimism on human nature. I can do this

Possibility of harmony and balance. I can do this

Complex interdependence. I can do this

Likelihood of global governance. I can do this

Impact and growth of international organisations. I can do this

Wording above is the Pearson specification, unchanged. Tick a line only when you could answer a question on it without notes.

Past questions - how it has been examined

Directly: 2020 Q2 (complex interdependence vs the security dilemma); 2021 Q2 (impact of international organisations and the significance of states).
Partially: Sample Q2 (human nature); 2024 Q2 (anarchical society).

What examiners reward and penalise

Stronger: tie optimism about human nature to the belief in cooperation and institutions.
Weaker: describe liberalism as naive without engaging its logic.
Praised: complex interdependence and democratic peace as named concepts.

One way to get high marks

Credited: institutions and interdependence soften anarchy.
Evidence: the EU; growth of the UN and WTO; US-China trade.
Level 5: tests liberalism against recent setbacks (Ukraine).

Full official mark schemes for every Paper 3 Global question, year by year: open the Paper 3 Global mark scheme viewer.

Arguments and counter-arguments

Does liberalism best explain global politics?

Yes

Point. Cooperation between states is real and widespread. Explanation. International institutions make collective action possible by bringing states together under shared rules. Example. The EU and the UN both show states acting together through institutions. Evaluation. These institutions falter when hard security issues are at stake, however.
Point. Interdependence makes states less likely to fight each other. Explanation. Because states depend on each other economically, war is simply too costly to be worth it. Example. The web of global trade ties states' interests together. Evaluation. Yet interdependence did not prevent the war in Ukraine, which limits this argument.

No

Point. Anarchy has not gone away. Explanation. Major war has returned to global politics, just as realists expect in an anarchic system. Example. The invasion of Ukraine in 2022 is the clearest case. Evaluation. This supports the realist reading of global politics rather than the liberal one.
Point. International institutions are weaker than liberals claim. Explanation. When their interests are at stake, powerful states simply ignore institutions. Example. The paralysis of the UN shows this weakness. Evaluation. Even so, institutions still shape how most states behave most of the time.

Best judgement. Liberalism explains the dense cooperation and interdependence of modern politics, but its optimism is strained by the return of great-power war, so it is strongest in peacetime and weakest in crises.

Using it in essays

12-mark (Q2): liberal vs realist on interdependence, institutions, human nature.
Topic sentence: "For liberals, interdependence and institutions make cooperation, not conflict, the natural state of affairs."

Practise this on PantherComparative theories walkthrough Comparative theories notes Realism v liberalism MCQ

Wider context

Helpful context

The EU is the liberal showpiece: complex interdependence making war between members almost unthinkable.

Examination priority

Essential Liberalism is the other half of every theory (Q2) question.

Named liberals: a sentence or two is enough

The same applies on the liberal side: a sentence each is all an answer needs.

Keohane	Institutions make cooperation rational under anarchy by cutting the costs of trust, so cooperation can outlast the conditions that created it. Use for UN, WTO and regime effectiveness.
Doyle	Democratic peace: democracies almost never fight each other, so spreading democracy makes the system safer. Use for the liberal case on world order.
Nye	Soft power and complex interdependence: states are tied together by many channels, so military force loses its primacy. Links this page to soft power in area 4.

Note that the most-quoted thinkers do not all fit one camp: Bull sits between the two, which is exactly why 6.4 treats him separately. Saying so is itself a Level 5 move.

6.3 Divisions between realism and liberalism Done

Essential Where the two theories clash.

The specification

6.3Divisions between realism and liberalism

Key terminology - tick the terms you can define: Realism Liberalism Power Conflict

human nature and power I can do this

order and security and the likelihood of conflict I can do this

impact of international organisations and the significance of states. I can do this

Wording above is the Pearson specification, unchanged. Tick a line only when you could answer a question on it without notes.

Past questions - how it has been examined

Directly: 2022 Q2 (human nature and power); 2021 Q2 (international organisations and significance of states); 2023 Mock Q2 (order, security and the likelihood of conflict); the Section B example (positions on the significance of states).
Partially: every Q2 is a division question in some form.
Also asked (2023 on): 2025 Q2 (inevitability of war).

What examiners reward and penalise

Stronger: organise by the point of division, debating both theories under each.
Weaker: describe each theory separately with no comparison.
Remember: Q2 carries no AO3, so no intro, conclusion or judgement.

One way to get high marks

Credited: precise contrasts on human nature, conflict and institutions.
Evidence: Hobbes vs Locke; the security dilemma vs complex interdependence.
Level distinction: the best answers analyse the division, not just state it.

Full official mark schemes for every Paper 3 Global question, year by year: open the Paper 3 Global mark scheme viewer.

Arguments and counter-arguments

The core divisions (use these as the analytical spine):

Human nature: realists pessimistic (Hobbes), liberals optimistic (Locke, Mill).
Order and conflict: realists expect war under anarchy; liberals expect cooperation through interdependence.
Institutions and states: realists see states as supreme and institutions as weak; liberals see institutions as genuinely shaping behaviour.

Note. This is a 12-mark analysis question with no AO3: compare precisely and do not reach a judgement.

Using it in essays

12-mark (Q2): analyse the divisions on a named point.
Structure: one paragraph per division, realism then liberalism, no conclusion.

Practise this on PantherComparative theories walkthrough Realism v liberalism judgement grid Theories paragraph builder

Wider context

Helpful context

The Hobbes-versus-Locke-and-Mill contrast on human nature is the root from which the other divisions grow.

Examination priority

Essential This is exactly what the Q2 theory question asks.

6.4 Anarchical society and the society of states Done

Important Order without a world government.

The specification

6.4Main ideas of the anarchical society and society of states theory

Key terminology - tick the terms you can define: Anarchical society and society of states International anarchy

Acceptance that there is anarchy in the global system - absence of overarching authority. I can do this

States have an informal understanding that ensures a degree of co-operation - based on norms and rules that increase levels of trust and reciprocal behaviour. I can do this

Wording above is the Pearson specification, unchanged. Tick a line only when you could answer a question on it without notes.

Past questions - how it has been examined

Directly: 2024 Q2 (how realism and liberalism differ over the anarchical society and society of states theory).
Partially: any Q2 on order and institutions.

What examiners reward and penalise

Stronger: present it as the middle path between realism and liberalism.
Weaker: confuse anarchy with chaos.
Praised: Hedley Bull named and used.

One way to get high marks

Credited: order can exist without a world government, through shared norms.
Evidence: the UN, international law, diplomacy as the 'society' of states.
Level 5: positions the theory against both realism and liberalism.

Full official mark schemes for every Paper 3 Global question, year by year: open the Paper 3 Global mark scheme viewer.

Arguments and counter-arguments

Can there be order without a world government?

Yes (society of states)

Point. Shared norms and rules bind states together. Explanation. States cooperate even though there is no world ruler to make them. The norms themselves do the work. Example. International law and everyday diplomacy show this informal order in action. Evaluation. These norms can break down when states come under serious pressure, however.
Point. Reciprocity, where states treat others as they themselves are treated, builds trust. Explanation. Because cooperation serves every state's interests, mutual interest keeps the order going. Example. Most treaties are kept, most of the time. Evaluation. Critics would say this order is self-interested at root rather than genuinely shared.

No (pure realism)

Point. Anarchy forces states into self-help. Explanation. When the rules clash with a state's vital interests, the rules get ignored. Example. The war in Ukraine showed international rules being set aside. Evaluation. Yet most rules hold most of the time, which this view struggles to explain.
Point. There is no enforcer standing above states. Explanation. Without enforcement, norms lack teeth and depend on states choosing to follow them. Example. The paralysis of the UN shows what happens when norms cannot be enforced. Evaluation. Even so, norms still shape what states expect of each other.

Best judgement. The society-of-states view is the persuasive middle path: anarchy is real but tempered by shared norms, which is why order mostly holds even without a world government.

Using it in essays

12-mark (Q2): how realism and liberalism differ over the anarchical society.
Topic sentence: "For the society-of-states view, anarchy is real but not chaotic: shared norms produce order without a ruler."

Practise this on PantherComparative theories walkthrough Comparative theories notes

Wider context

Helpful context

Think of it as realism's anarchy plus liberalism's cooperation: the bridge between the two main theories.

Examination priority

Important A named theory the spec requires; tested directly in 2024.

6.5 Do realism and liberalism explain developments since 2000? Done

Essential Applying the theories to recent events.

The specification

6.5Evaluation of the extent to which realism and liberalism explain recent developments

Key terminology - tick the terms you can define: Realism Liberalism Case studies

An evaluation of the extent to which realism and liberalism explain recent developments (since 2000) in global politics, through the study of relevant case studies that cover each of the other content sections: the state and globalisation; global governance: political and economic; global governance: human rights and environmental; power and developments; regionalism and the EU. I can do this

Wording above is the Pearson specification, unchanged. Tick a line only when you could answer a question on it without notes.

Past questions - how it has been examined

Directly: 2023 Q2 (different explanations realism and liberalism provide for developments since 2000).
Partially: the theory frame for evaluating most 30-mark questions.

What examiners reward and penalise

Stronger: draw case studies from across the paper and judge which theory fits each.
Weaker: rely on one example for the whole answer.
Praised: synoptic range across the content areas.

One way to get high marks

Credited: each theory explains different developments; neither explains all.
Evidence: Ukraine (realism); the EU and global trade (liberalism); the stall of liberal democracy (realism).
Level 5: reaches a balanced, evidenced verdict on explanatory power.

Full official mark schemes for every Paper 3 Global question, year by year: open the Paper 3 Global mark scheme viewer.

Arguments and counter-arguments

Which theory better explains developments since 2000?

Realism

Point. Since 2000, war and great-power rivalry have returned to global politics. Explanation. Power politics, not cooperation, has dominated the headline events of the period. Example. The Ukraine war of 2022 and the US-China rivalry are the leading examples. Evaluation. This account misses the dense cooperation that continues underneath the crises, however.
Point. The spread of liberalism has stalled. Explanation. The rise of authoritarian capitalism shows that states can grow rich without becoming liberal democracies. Example. Democratic backsliding around the world supports this view. Evaluation. Even so, liberal institutions persist and have not collapsed.

Liberalism

Point. Cooperation between states has deepened since 2000. Explanation. Institutions now reach into almost every area of global politics. Example. Global trade, the EU and international climate talks all show this. Evaluation. These forms of cooperation falter in moments of crisis, however.
Point. Interdependence between states endures despite the return of conflict. Explanation. War remains hugely costly for states whose economies are tied together, so most still avoid it. Example. Global supply chains link economies across the world. Evaluation. But interdependence did not prevent the war in Ukraine, which weakens the liberal case.

Best judgement. Realism explains the headline events since 2000 (war, rivalry, the stall of liberalism) better, but liberalism still explains the dense everyday cooperation, so each captures a different layer of global politics.

Using it in essays

12-mark (Q2): explanations realism and liberalism provide for developments since 2000.
Topic sentence: "Realism explains the crises since 2000 and liberalism the cooperation, so the two theories describe different layers of the same world."

Practise this on PantherComparative theories walkthrough Which theory explains it judgement grid Comparative theories quiz

Wider context

Helpful context

This subsection rewards synoptic range: bring in one case study from each content area.

Examination priority

Essential The synoptic evaluation the spec builds toward.

Map Timeline (interactive roller)

Helpful context

Developments since 2000 and whether realism or liberalism explains them better. The case-study spine for 6.5.

Roll through the timeline1 / 6

20019/11

2003Iraq

2008Crisis

2011Arab Spring

2014Crimea

2022Ukraine

2001

9/11. Non-state terror and the 'war on terror' challenge the liberal optimism of the 1990s.

2003

Iraq War. Unilateral US action and its aftermath strengthen the realist reading of power politics.

2008

Global financial crisis. Interdependence as both cooperation (G20) and vulnerability (contagion).

2011

Arab Spring and Libya. Hopes of liberal change give way to chaos and selective intervention.

2014

Crimea. Russia revises borders by force: the balance of power and the security dilemma return.

2022

Ukraine. Full-scale war between great-power blocs: the strongest recent evidence for realism.

Roll up and down: the arrows, scroll or swipe inside the box, the up and down keys, or click a year above.

Diag Diagram: realism and liberalism at a glance

Exam use: Q2 is realism against liberalism every year - only the angle changes. Learn the grid and you can rebuild any angle (sovereignty, war, institutions, globalisation) from the same five rows.

Plan Where the essays come from

Each row takes a theory pairing the specification names, quoted word for word, and shows the 12-mark question it tends to become. Learn both lines for every row.

The spec wording	The question this becomes	The two sides in one line
"human nature and power"	Examine the differences between realism and liberalism on human nature and power.	Realist: people and states are self-interested, so power is the only reliable currency. Liberal: people are capable of moral progress, so power can be tamed by institutions.
"order and security and the likelihood of conflict"	Examine the differences between realism and liberalism on order, security and the likelihood of conflict.	Realist: international anarchy and the security dilemma make war inevitable. Liberal: interdependence and institutions make harmony and balance possible.
"impact of international organisations and the significance of states"	Examine the differences between realism and liberalism on international organisations and the state.	Realist: organisations are tools of their strongest members; states remain the key actors. Liberal: organisations grow a life of their own and point toward global governance.
"The security dilemma"	Examine how the security dilemma and complex interdependence lead realists and liberals to opposite conclusions.	Realist: each state arming for defence makes every other state less safe. Liberal: states tied together by trade and institutions cannot afford the spiral.
"Main ideas of the anarchical society and society of states theory"	Examine the differences between the society of states theory and the realist view of international anarchy.	Realist: anarchy means self-help and recurring war. Society of states: anarchy is softened by norms, rules and reciprocal trust.
"An evaluation of the extent to which realism and liberalism explain recent developments"	Examine how realists and liberals each explain developments in global politics since 2000.	Realist: Ukraine, rivalry and the return of war vindicate the state and power. Liberal: institutions, trade and climate cooperation survived every shock.

Sum Section summary - the must-knows

1Facts most worth memorising

Realism: states are key actors in an anarchic, self-help system.
Realism sees the balance of power, the security dilemma and the likelihood of war.
Realist human nature is pessimistic (Hobbes).
Liberalism: optimism about human nature (Locke, Mill) and the possibility of cooperation.
Liberalism stresses complex interdependence and the growth of institutions.
Democratic peace theory: established democracies do not fight each other.
The security dilemma: a defensive move by one state looks like a threat to another.
Complex interdependence: economic ties raise the cost of war.
The anarchical society (Hedley Bull): anarchy without chaos, order through norms.
Realism and liberalism each explain different developments since 2000.

2Examples most worth memorising

Ukraine 2022 (realism)
US-China rivalry (realism)
The EU (liberalism)
Growth of the UN and WTO (liberalism)
NATO expansion and the security dilemma
US-China trade (complex interdependence)
The UN and international law (society of states)
Democratic peace theory
Hobbes vs Locke and Mill (human nature)
Realism's resurgence since 2000 (Iraq, Ukraine)

3Evaluation points most worth memorising

Anarchy makes conflict structural for realists.
Interdependence and institutions soften anarchy for liberals.
The security dilemma explains escalation without anyone wanting war.
Realism is strongest in crises, liberalism in peacetime.
The society-of-states view is the persuasive middle path.
Q2 carries no AO3: compare, do not judge.
Human nature is the root division (Hobbes vs Locke).
Each theory explains a different layer of politics.
Realism explains the headlines since 2000; liberalism the everyday cooperation.
Institutions shape behaviour even when they lack teeth.

4Examiner warnings to act on

For Q2, organise by the point of division and do not reach a judgement.
Link realist concepts together (anarchy, self-help, security dilemma).
Do not confuse anarchy with chaos.
Apply theory to recent events, not just abstract ideas.
Name thinkers: Hobbes, Locke, Mill, Hedley Bull.

5Strongest essay arguments

Realism explains conflict and rivalry; liberalism cooperation and institutions.
Anarchy drives self-help, which drives the security dilemma.
Interdependence and institutions make war costly but not impossible.
The society-of-states view bridges the two theories.
Each theory captures a different layer of post-2000 politics.

Test Section test - 12 questions

Twelve mixed questions covering the whole section. Your most recent score is shown in the top bar.

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