AP Syllabus focus:
‘Analyze how the Cold War’s end and the post-9/11 focus on terrorism reshaped foreign policy and Americans’ understanding of U.S. power in the world.’
U.S. Global Role from the Cold War’s End to the War on Terror
The collapse of the Soviet Union and the rise of global terrorism transformed U.S. foreign policy, shifting strategic priorities, military commitments, and Americans’ perceptions of national power.
The Post–Cold War International Landscape
With the Cold War’s end in 1991, the United States emerged as the world’s dominant military, economic, and diplomatic force. Policymakers debated how this new position should shape long-term strategy.
When the Soviet Union dissolved, the United States found itself in what analysts called a unipolar world, a concept introduced to describe a system dominated by one superpower.
Unipolarity: A global power structure in which one state holds predominant military, economic, and political influence over international affairs.
This new order allowed the United States to steer global institutions, promote market-oriented reforms abroad, and expand alliances such as NATO, which later admitted former Eastern Bloc nations. Expanded NATO commitments, however, raised questions about the scope of U.S. responsibilities in regional conflicts and global security initiatives.
As American policymakers reassessed strategy, they faced growing debates over how assertively the nation should project power. Some leaders championed active engagement to maintain stability and promote democratic values, while others emphasized restraint, warning that overextension risked entanglement in regional crises.
Military Interventions and Peacekeeping After the Cold War
Without the bipolar constraints of U.S.–Soviet rivalry, American leaders had new freedom to intervene in humanitarian, peacekeeping, and regional conflicts. These interventions shaped a new understanding of U.S. responsibility in the world.
Key Patterns in U.S. Post–Cold War Interventions
• Humanitarian interventions in Somalia and the Balkans aimed to stop ethnic violence and famine.
• Peacekeeping operations often blended military force with diplomatic negotiation.
• Coalition-based actions highlighted the United States’ leadership role in multinational organizations.
These engagements raised domestic debates about when military intervention was justified and whether the United States should act unilaterally or with allied support. American public opinion frequently shifted depending on casualties, mission clarity, and the perceived national interest.
Economic Globalization and Leadership
The United States also redefined its global role through economic leadership. American support for free-trade agreements—such as NAFTA and the creation of the World Trade Organization—reflected confidence in U.S. economic dominance and the belief that global markets would advance national prosperity.
However, critics argued that globalization produced economic inequalities at home and eroded manufacturing sectors. These tensions influenced how Americans evaluated the benefits and costs of U.S. leadership in global economic institutions.
9/11 and the Transformation of U.S. Foreign Policy
The terrorist attacks of September 11, 2001 radically reoriented American foreign policy around combating terrorism, a term broadly referring to the use of violence by non-state actors to achieve political aims.
Terrorism: The use or threat of violence by individuals or groups—often non-state actors—to intimidate societies or governments for political objectives.
After 9/11, Americans confronted an entirely different security environment. National leaders framed terrorism as a global, long-term threat requiring proactive measures both abroad and at home. This shift marked one of the most profound redefinitions of national power since World War II.
On September 11, 2001, al-Qaeda terrorists hijacked four planes and crashed them into the World Trade Center, the Pentagon, and a field in Pennsylvania, killing nearly 3,000 people and convincing many Americans that even the world’s leading superpower was vulnerable to non-state terrorism.
Aerial image of the World Trade Center site shortly after 9/11, with overlays marking original building locations. The visual clarifies the scale of destruction that reshaped U.S. foreign policy. Some numerical building labels exceed syllabus needs but help contextualize the site geographically. Source.
The “Global War on Terror” and the Assertion of U.S. Power
In response to 9/11, the United States launched a Global War on Terror (GWOT), a strategy that emphasized preemption, coalition-building, and broad military engagement.
Core Elements of the Post-9/11 Strategy
• Intervention in Afghanistan to dismantle al-Qaeda and remove the Taliban regime that harbored it.
• The 2003 Iraq War, justified by claims about weapons of mass destruction and fears of state-sponsored terrorism.
• Expanded intelligence and surveillance, intended to prevent future attacks.
• Strengthened alliances with states supporting counterterror operations.
These actions demonstrated an unprecedented willingness to use military force to address non-state threats, reinforcing perceptions of overwhelming U.S. global power. Yet the prolonged conflicts also generated debates about the limits of American influence and the long-term viability of unilateral or preemptive action.
In 2003, the Bush administration launched a larger and more controversial invasion of Iraq, justified by claims that Saddam Hussein possessed weapons of mass destruction and had links to terrorism, even though these justifications were heavily disputed and later found to be flawed.
Map of U.S. and British ground advances into Iraq during the 2003 invasion, illustrating how coalition forces projected military power across the region. The operational arrows show general directions of movement, though unit-level detail exceeds the AP syllabus and can be skimmed by students. Source.
Changing Understandings of American Power
The combination of Cold War victory and post-9/11 security challenges reshaped Americans’ views of their country’s global role. Many believed the United States had a responsibility to use its unmatched military capabilities to preserve global stability. Others argued that expansive military commitments drained resources, damaged international credibility, and complicated diplomatic relationships.
Factors Influencing National Perceptions of U.S. Power
• Military commitments across multiple regions strained personnel and budgets.
• Allied cooperation varied, affecting the legitimacy of U.S. actions.
• Domestic debates intensified over civil liberties, national identity, and the definition of security.
• Global reactions to U.S. interventions shaped how Americans assessed foreign approval or criticism of national policy.
As the United States confronted new threats and evolving geopolitical dynamics, these debates continued to influence public discourse and policy decisions, revealing how profoundly post-1980 developments redefined ideas about American power.
FAQ
Many nations expected the United States to act as a stabilising force because it held unmatched military and economic power.
This resulted in growing pressure for the U.S. to lead peacekeeping missions, enforce international norms, and manage regional conflicts.
However, some countries criticised this dominance, arguing it allowed the United States to act unilaterally without sufficient global oversight.
Although framed as moral obligations, humanitarian missions often lacked clear strategic goals, raising doubts about their value.
Controversy developed because:
• operations risked American casualties in conflicts unrelated to core national interests
• outcomes were sometimes uncertain or limited
• they prompted debates about whether the U.S. should be the world's primary crisis responder
Many allies initially supported U.S. objectives after 9/11, viewing the attacks as an assault on shared democratic values.
As the Iraq War unfolded, however, global opinion became more divided. Critics argued that the U.S. applied its military power too broadly, undermining diplomatic legitimacy and trust.
Supporters maintained that assertive action was necessary to address evolving threats in an unstable international environment.
Critics claimed pre-emption weakened long-standing norms against initiating conflict.
They argued that:
• intelligence used to justify pre-emption could be flawed
• such actions risked destabilising regions
• the approach encouraged other nations to invoke pre-emption for their own aims
The doctrine also raised ethical concerns about acting before a threat fully materialised.
The wars intensified disagreements about the limits of American power, the costs of extended military commitments, and the proper balance between security and civil liberties.
Public opinion fractured between those supporting robust counterterror strategies and those questioning the strategic purpose, financial cost, and human impact of long-term conflict.
These debates contributed to shifting party priorities, electoral outcomes, and growing public scepticism toward overseas military engagements.
Practice Questions
(1–3 marks)
Explain one way in which the end of the Cold War altered the global role of the United States.
Question 1 Mark Scheme (1–3 marks)
Award marks for any of the following, up to a maximum of 3:
• 1 mark for identifying a valid change in U.S. global role after the Cold War (e.g., emergence as the sole superpower, increased willingness to intervene abroad).
• 1 mark for describing the change with some detail (e.g., expansion of NATO, shift toward humanitarian or peacekeeping missions).
• 1 mark for explaining why the end of the Cold War enabled this change (e.g., absence of Soviet rivalry allowed more freedom of action).
High-scoring answers should clearly connect the change to the collapse of the Soviet Union and the resulting unipolar world.
(4–6 marks)
Analyse how the 9/11 attacks reshaped U.S. foreign policy and Americans’ understanding of national power in the early 21st century.
Question 2 Mark Scheme (4–6 marks)
Award marks based on the following criteria:
• 1–2 marks: Identifies basic consequences of 9/11 for U.S. foreign policy (e.g., the start of the War on Terror, invasions of Afghanistan and Iraq).
• 1–2 marks: Provides explanation of how policy shifted (e.g., focus on pre-emption, expansion of surveillance, building international coalitions).
• 1–2 marks: Analyses how Americans’ perception of national power changed (e.g., increased sense of vulnerability, belief in the need for assertive global action, debates over limits of U.S. influence).
Answers earning 6 marks will offer clear, accurate analysis linking the attacks to broader debates about America’s global role and strategic priorities.
