The Blockade: Lesson Plan

Overview

This lesson uses the 1951 Abadan Crisis to explore how economic warfare, sovereignty, and unintended consequences shape international relations. Students compare Britain's 1951 naval blockade of Iran with the 2026 US blockade, examining how the same tactic in the same waterway produced cascading consequences across 75 years.

Subject areas: World History, International Relations, Economics, Geography Grade levels: 9-12, AP World History, AP Government Duration: 1-2 class periods (45-90 minutes)

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Essential Questions

1. When does economic pressure cross the line from diplomacy into coercion?

1. How do short-term foreign policy "wins" create long-term strategic problems?

1. Who has the right to control a nation's natural resources?

1. How does geography (chokepoints like the Strait of Hormuz) shape the balance of power?

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Learning Objectives

Students will be able to:

• Explain the causes and consequences of the 1951 Abadan Crisis

• Analyze the concept of resource sovereignty and its limits under international law

• Evaluate the effectiveness of naval blockades as instruments of foreign policy

• Trace a causal chain from the 1953 coup through the 1979 Revolution to the present conflict

• Compare historical and contemporary uses of economic warfare

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Key Vocabulary

• Nationalization: When a government takes control of privately owned industry or assets

• Naval blockade: Using warships to prevent trade in or out of a port or country

• Concession: A grant of rights to operate in a territory, often for resource extraction

• Sovereignty: The authority of a state to govern itself and control its territory

• Unintended consequences: Outcomes of an action that were not anticipated or intended

• Chokepoint: A narrow passage through which shipping must pass (e.g. Strait of Hormuz)

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Activities

Activity 1: The Numbers Tell the Story (15 min)

Present students with the 1950 AIOC financial breakdown:

• AIOC total profit: £40 million

• Paid to British government in taxes: £36 million

• Paid to Iran in royalties: £16 million

• Aramco's deal with Saudi Arabia: 50-50 split

Discussion prompts:

• If you were an Iranian citizen in 1951, how would you react to these numbers?

• Why might Britain have refused a 50-50 deal when Aramco had already agreed to one?

• Is there a difference between nationalizing oil and "stealing" it?

Activity 2: The Blockade Decision Tree (20 min)

Students work in groups representing British, Iranian, and American decision-makers. Each group receives the same timeline of events (March 1951 to August 1953) and must identify the decision points where a different choice could have changed the outcome.

Key decision points to examine:

• Britain's refusal of 50-50 profit sharing (late 1950)

• Iran's unanimous nationalization vote (March 1951)

• Britain's choice of blockade over negotiation (summer 1951)

• Mossadegh's appeal to the ICJ (June 1952)

• The CIA's decision to proceed with the coup (August 1953)

Activity 3: The Causal Chain (20 min)

Students trace the chain of consequences from 1953 to 2026:

1. 1953: CIA/MI6 overthrow Mossadegh, restore the Shah

1. 1953-1979: Shah's authoritarian modernization alienates religious establishment

1. 1979: Islamic Revolution overthrows the Shah

1. 1979-1981: Iran hostage crisis, 444 days

1. 1980-1988: Iran-Iraq War (US supports Iraq)

1. 2002-2015: Iran nuclear program standoff

1. 2026: US-Iran war, naval blockade

Discussion: At which link in this chain could the sequence have been broken? Is the 2026 war really a consequence of the 1953 coup, or is that an oversimplification?

Activity 4: Comparing Blockades (15 min)

Create a two-column comparison: | | Britain 1951 | United States 2026 | |---|---|---| | Target | Iran's oil exports | Iran's all maritime trade | | Mechanism | Royal Navy intercepts tankers | US Navy blockades ports | | Stated justification | Oil is "stolen property" | Wartime measure | | International legal basis | Disputed (ICJ declined jurisdiction) | Disputed | | Economic impact on Iran | Oil exports dropped to near zero | Strait of Hormuz traffic down 90% | | Third-party mediator | None (UN, World Court tried) | Pakistan | | Outcome | ? | ? (ongoing) |

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Primary Source Analysis

• TIME magazine's 1951 Man of the Year article on Mossadegh

• ICJ Judgment of 22 July 1952 (Anglo-Iranian Oil Co. case)

• CIA declassified documents on Operation Ajax (released 2013)

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Assessment Options

1. Essay: "The blockade worked. What came after didn't." Evaluate this statement with reference to both the 1951 and 2026 blockades.

1. Policy memo: Write a one-page memo advising the current administration on what the 1951 precedent suggests about the likely long-term consequences of the 2026 blockade.

1. Timeline project: Create an annotated timeline from 1901 (D'Arcy Concession) to 2026 showing how oil has shaped the US/UK-Iran relationship.

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Extension Activities

• Research the Anglo-Persian War of 1856-57, when Britain blockaded Bushehr (the same Persian Gulf port) to force Iran to give up claims on Herat. This is the THIRD time a Western power has blockaded Iranian ports.

• Compare Iran's nationalization of oil (1951) with Mexico's nationalization of oil (1938). Why did Mexico succeed and Iran fail?

• Investigate the role of the Strait of Hormuz in global energy security. What percentage of world oil passes through it? What happens to global markets when it closes?