Key Takeaways

Domestic Dynamics Are Central to U.S. War Policy: The Iran war highlighted the importance of domestic dynamics in shaping U.S. war policy. Public support and political unity are now just as important as military strength in sustaining a war.

Fragmented Politics and the Media Are Shaping War Trajectories: Public opinion, congressional dynamics, and media fragmentation are increasingly redefining the scope, escalation, and duration of U.S. military operations, deciding the continuation and end of wars.

Cross-Partisan War Fatigue Is Narrowing Strategic Options: War fatigue now cuts across partisan lines, narrowing the domestic consensus for prolonged foreign interventions and reinforcing pressure to prioritize internal economic and institutional development.

The U.S. Political Economy of War Is a Decisive Factor: Rising defense costs, fiscal pressures, and competing domestic priorities are increasingly limiting the sustainability of large-scale military engagements.

Introduction

The US-Israel-Iran war has extended well beyond the Middle East battlefield. In addition to its effects on global markets and supply chains, the war has had significant political consequences in Washington, reshaping domestic politics and influencing public opinion. As the tension escalated in early 2026, the Trump administration faced mounting pressure from both sides of the aisle, with intense partisan debate over the justification and goals of U.S. military involvement in Iran. These divisions stem from broader ideological differences: Republican supporters generally emphasize deterrence and national security, while Democratic critics argue that the war risks a protracted and costly engagement that comes at the expense of domestic priorities, a polarization also reflected in public opinion.

Previous American foreign wars had tested both the country’s military capability and domestic cohesion. From the Vietnam War, which produced one of the deepest social rifts in modern American history, to the wars in Iraq and Afghanistan, which gradually eroded political will and fiscal resilience over two decades, the relationship between the external front and the home front has remained a decisive factor in shaping the trajectory of American military engagements abroad. The war with Iran follows this pattern, though in a more complex international context and a more deeply polarized domestic environment.

This issue brief examines the domestic impacts of the war with Iran across six dimensions to assess whether the U.S. can sustain a large-scale foreign conflict when the fiscal capacity and public trust required to support it are under severe strain, namely: (I) partisan political polarization, (II) media dynamics and narrative construction, (III) shifts in public opinion, (IV) economic pressures, (V) the escalating cost of defense and national security, and finally (VI) the psychological–strategic dimension and its implications for the future of America’s role in the world.

I. Deepening Divide

Since its onset, the war with Iran has divided the American political establishment over the fundamental principles of national security. Republicans largely framed the confrontation as a strategic necessity to prevent Iran from altering the regional balance of power in its favor, safeguard global energy security, and protect the interests of Washington’s traditional allies in the Gulf and the broader Middle East.¹ In contrast, a broad contingent of Democrats feared that the military engagement would lead to a prolonged and costly war, evoking in America’s political memory the experiences of Iraq and Afghanistan, with all their human, financial, and institutional costs.²

However, this divide went beyond the familiar partisan binary on foreign policy; rather, it reflected a deeper structural transformation in American strategic thinking. Republican supporters of the war framed their position around rebuilding deterrence as a prerequisite for regional stability, arguing that allowing Iran to expand its nuclear capabilities and regional influence would undermine the strategic position of the U.S. and its allies in the Middle East.³ The Democratic current, particularly its progressive wing, has emphasized prioritizing diplomacy over external military commitments, with the view that genuine American strength is built by redirecting resources toward domestic renewal,⁴ addressing everything from deteriorating public infrastructure to widening economic inequality.

As the military operations continued and the operational landscape grew more complex, the debate shifted to Congress in an increasingly heated and politicized way, centering on three pivotal issues: the scope of presidential authority to use military force without expanded congressional authorization under the War Powers Act;⁵ the scale of additional defense appropriations and their funding sources amid a ballooning federal deficit;⁶ and the prospect of deploying ground forces on Iranian territory, an option that continued to face opposition at both the popular and institutional levels, effectively becoming the unspoken red line in the domestic political debate.⁷

II. Manufacturing Parallel Narratives

American media played a central role in deepening domestic polarization over the war.⁸ In this context, the Trump administration, through the Department of War, moved to restrict access to its war briefings in ways that favored right-leaning outlets, thereby influencing the information environment around the war, a policy that was later challenged in federal court and ruled unlawful.⁹

Conservative media platforms supportive of the war, led by right-leaning television networks and influential podcast channels, focused on amplifying the Iranian threat to American national security and Washington’s allies, while emphasizing the necessity of military decisiveness and portraying any hesitation as a strategic weakness that would embolden U.S. adversaries. In contrast, liberal-leaning media outlets focused on the risks of miscalculated escalation, the likelihood of sliding into a regional war, and the anticipated human and economic costs, with frequent invocation of lessons from previous wars that ended in catastrophe. These media dynamics produced two parallel narratives of the war.

The first presented the war as a strategic necessity to neutralize a direct and growing threat to American security, Israeli survival, and regional stability, framing the confrontation as a test of American resolve against a regional adversary that had long threatened Washington and its allies. The second portrayed the war as an unauthorized military intervention with unpredictable consequences that risked draining American economic resources without achieving decisive outcomes, thereby raising concerns about the cycle of endless wars that had already damaged America’s standing and resources.

This media polarization reinforced the phenomenon of ‘echo chambers’—now a structural feature of the contemporary American media landscape—whereby American citizens receive fundamentally different accounts of the same conflict depending on their political affiliation and preferred media sources.¹⁰ This phenomenon deepened the crisis of eroding trust in both political and media institutions and prevented the formation of a national consensus on the war’s objectives and acceptable boundaries, rendering the management of public discourse around the conflict almost as challenging as managing military operations themselves.

III. Shifts in Popular Sentiment

Opinion polls conducted throughout the war reveal a clear gap between the discourse of political elites and the priorities of ordinary American citizens. The data show that Americans have been far more preoccupied with the war’s direct human and economic costs than with its declared geopolitical objectives. According to an Ipsos poll, approximately 86% of respondents remain very or somewhat concerned about the risk to the lives of American military personnel, while 77% remain very or somewhat concerned about the escalating financial cost of the conflict and its impact on the federal budget and public services. The same poll found that the majority (76%) of respondents oppose deploying U.S. ground forces into Iran.¹¹

These indicators reflect a deep structural shift in American popular sentiment, crystallized gradually over more than two decades of continuous military engagement abroad since the events of September 11, 2001. American society has become less willing to accept open-ended wars with undefined timelines, and more inclined to hold decision-makers accountable for the returns of military interventions, and more sensitive to the trade-offs between military spending and investment in social and economic development, such as in healthcare, education, and infrastructure.

In this context, the war with Iran has contributed to reviving what may be termed ‘strategic retrenchment sentiment,’ a growing orientation among broad segments of the electorate that the national priority should be directed toward rebuilding the American interior, economically, socially, and institutionally, rather than embroiling the country in distant conflicts with uncertain outcomes. Notably, this sentiment is no longer confined to the progressive base of the Democratic Party but extends to growing segments of the populist base within the Republican Party, particularly Republican-leaning independents,¹² and even some who embrace the ‘America First’ discourse with its isolationist undertones.¹³

IV. Economy Under Geopolitical Strain

The U.S. has not been insulated from the direct and indirect economic repercussions of the confrontation with Iran. The disruption of maritime navigation through the Strait of Hormuz, through which approximately one-fifth of global oil supplies transit, has led to a marked increase in international oil prices and a sharp rise in shipping and insurance costs, all of which directly impact inflation rates, fuel prices, and consumer goods within the domestic American market.¹⁴

These price surges heightened concerns about inflation. Sharp spikes in energy prices compress the average American’s purchasing power, disrupt the Federal Reserve’s calculations on interest rates, undermine market and investor confidence, and negatively affect the popularity of the incumbent administration, particularly in an economic environment that has not fully recovered from previous inflationary waves, or during electoral seasons in which gasoline prices function as a political indicator as much as an economic one.

Conversely, certain sectors benefit from this war. Chief among these are the defense and armaments industries, which have experienced increased demand for military systems and maintenance and supply contracts, as well as the domestic American energy sector, particularly shale oil producers, which have strengthened their competitive position amid declining supplies from the Gulf region and rising global crude prices.

However, the aggregate impact on the American economy remains ambivalent and subject to debate among economists. There are competing views that excessive expansion in military spending may provide a short-term growth stimulus through activating defense production chains and creating temporary employment, but over the medium- and long-term, it crowds out civilian investment, diminishes resources available to other sectors, and undermines the prospects for sustainable growth dependent on human capital and civilian infrastructure.¹⁵

V. Escalating Cost of Defense

The increase in defense and security spending has been one of the most direct domestic consequences of the war, at both the political and economic levels. The U.S. was compelled to reinforce its military presence across multiple and geographically dispersed theaters of operation, augment missile defense capabilities deployed in the region and aboard aircraft carriers, secure its forward military bases in the Gulf, Iraq, and the Indian Ocean, and protect international maritime trade routes passing through strategic chokepoints. These commitments impose escalating financial and logistical burdens that cannot be easily reduced even after the intensity of operations subsides.¹⁶

This expansion in spending by the Department of War extended well beyond conventional military operations to encompass the full spectrum of modern conflict costs. These costs include the need to bolster national cybersecurity systems against Iranian cyberattacks targeting sensitive infrastructure, to protect energy and communications networks from sabotage and infiltration operations, to monitor asymmetric threats that may target American interests through regional proxies, and to secure space-based communications and intelligence assets that have become an integral component of the cost and requirements of modern conflict.¹⁷

Against the backdrop of a worsening federal fiscal deficit that was already at historically elevated levels before the war,¹⁸ defense spending transformed from a technical security matter into a first-order economic and political issue. A growing number of economists, legislators, and budget experts began raising a fundamental question about whether the U.S. is gradually sliding toward what may be described as a security mobilization economy, in which the share of spending on defense and security steadily expands at the expense of social programs, investment in human capital, and civilian infrastructure. This pattern risks undermining American economic competitiveness over the long term.

VI. The Existential Question

The war with Iran raised a fundamental question within America’s political, intellectual, and academic elites, a question pertaining not to any war in particular but to the future of the American model itself: Is the U.S. still capable of managing a sprawling international order of commitments and responsibilities without significant cost to domestic cohesion and social stability?

Wars in the twenty-first century are no longer judged by territorial gains or the number of targets destroyed, but by their capacity to preserve the social and political cohesion of the state that wages them. The Iranian crisis revealed that Washington’s deepest challenge lies not on the battlefield, where the American military enjoys unrivaled technological and operational superiority, but in managing an internally deepening division between two competing and contradictory visions for the future of America’s global role:

The leadership-through-strength or ‘America First’ vision: Holds that the direct advancement of American national interests is best pursued through unilateral strength and transactional relationships, irrespective of international norms or institutional frameworks.

The domestic rebalancing vision: Considers that the overextension of foreign military interventions and excessive strategic presence has increasingly exhausted America’s economic resources and institutional capacity, and that reducing external commitments is not a sign of weakness but an intelligent reprioritization.

This divide extends well beyond the conventional partisan disagreement, reflecting a fracture in how Americans understand their country’s identity and role in the world, one whose impact on American foreign policy may prove deeper and more enduring than the outcome of any single battle.

Conclusion

The war with Iran has demonstrated that the American home front now constitutes a central constraint on U.S. war-making capacity—one no less important than battlefield military superiority or destructive firepower. Deepening partisan polarization, structural media division, growing public wariness of open-ended wars, accumulated economic pressures, and the escalating cost of defense amid chronic fiscal deficits limit any American administration’s space to maneuver and its ability to sustain a prolonged conflict without facing domestic blowback.

While Washington retains a clear and uncontested military and technological superiority for the foreseeable future, this war has exposed a political–societal challenge: How does a democratic superpower wage a large-scale foreign war without risking a domestic crisis that threatens its institutional cohesion, national consensus, and capacity for effective governance?

The most significant lesson emerging from this war is that the balance of power is increasingly shaped not only by battlefield dynamics and markets, but also by domestic political cohesion, public opinion, and media fragmentation within democratic societies—which, in turn, possess the power to draw the endpoints of wars before they conclude militarily. This is a reality that must remain at the forefront of any effort to understand the future of American power and its determinants.

Endnotes

¹ The White House, “President Trump’s Clear and Unchanging Objectives Drive Decisive Success Against Iranian Regime,” April 1, 2026, https://www.whitehouse.gov/releases/2026/04/president-trumps-clear-and-unchanging-objectives-drive-decisive-success-against-iranian-regime/.

² U.S. Senator Tim Kaine, “As Senate Republicans Fail to Act on Iran War, Senators Force New War Powers Vote & Meet with Veterans,” Tim Kaine U.S. Senator from Virginia, March 18, 2026, https://www.kaine.senate.gov/press-releases/as-senate-republicans-fail-to-act-on-iran-war-senators-force-new-war-powers-vote-and-meet-with-veterans; Lauren Fox and Sarah Ferris, “They Fought in Iraq. Now They’re the Democrats’ Loudest Voices Against the War in Iran,” CNN, March 5, 2026, https://www.cnn.com/2026/03/05/politics/iran-war-democrats-veterans.

³ Aaron Blake, “The Trump Team’s Shifting Story on War with Iran,” CNN, March 3, 2026, https://www.cnn.com/2026/03/02/politics/hegseth-rubio-trump-iran-messaging.

⁴ Congressional Progressive Caucus, “Congressional Progressive Caucus Adopts Official Position to Oppose Supplemental Funding for Iran War,” March 25, 2026, https://progressives.house.gov/2026/3/congressional-progressive-caucus-adopts-official-position-to-oppose-supplemental-funding-for-iran-war.

⁵ Scott Bombay, “Does the War Powers Resolution Debate Take on a New Context in the Iran Conflict?,” National Constitution Center, March 3, 2026, https://constitutioncenter.org/blog/does-the-war-powers-resolution-debate-take-on-a-new-context-in-the-iran-conflict.

⁶ Claudia Grisales, “Republicans in Congress Brace for a Fight Over the Iran War Price Tag,” NPR, April 10, 2026, https://www.npr.org/2026/04/10/nx-s1-5780016/iran-war-funding-republicans-congress.

⁷ Ipsos, “Majority of Americans Favor Exit from Iran Conflict, Even If Not All U.S. Goals Are Achieved,” Ipsos Iran War Tracking Poll, March 31, 2026, https://www.ipsos.com/en-us/majority-americans-favor-exit-iran-conflict-even-if-not-all-us-goals-are-achieved; Nik Popli, “What Would a U.S. Win in Iran Look Like? We Asked Over Two Dozen Members of Congress,” TIME Magazine, March 26, 2026, https://time.com/article/2026/03/26/we-asked-members-of-congress-what-winning-the-iran-war-would-look-like/.

⁸ Daniel Dale, “Fake, AI-generated Images and Videos of the Iran War Are Spreading on Social Media,” CNN, March 11, 2026, https://www.cnn.com/2026/03/11/politics/fake-ai-images-videos-iran-war.

⁹ Brian Stelter, “The Pentagon’s Press Crackdown Meets Some Real Resistance,” CNN, March 21, 2026, https://edition.cnn.com/2026/03/21/media/hegseth-pentagon-press-new-york-times-judge-ruling.

¹⁰ Luca Braghieri et al., “Article-level Slant and Polarization of News Consumption on Social Media,” VOX-EU CEPR, April 17, 2025, https://cepr.org/voxeu/columns/article-level-slant-and-polarisation-news-consumption-social-media.

¹¹ Ipsos, “Majority of Americans Favor Exit from Iran Conflict, Even If Not All U.S. Goals Are Achieved.”

¹² Pew Research Center, “Americans Broadly Disapprove of U.S. Military Action in Iran,” March 25, 2026, https://www.pewresearch.org/politics/2026/03/25/americans-broadly-disapprove-of-u-s-military-action-in-iran/.

¹³ Domenico Montanaro and Steve Inskeep, “New Poll Shows Americans are Skeptical of Trump’s Iran War,” NPR, March 11, 2026, https://www.npr.org/2026/03/11/nx-s1-5743799/new-poll-shows-americans-are-skeptical-of-trumps-iran-war.

¹⁴ Claudia Grisales, “Republicans in Congress Brace for a Fight Over the Iran War Price Tag.”

¹⁵ International Monetary Fund, “Wars Impose Lasting Economic Costs, While More Defense Spending Means Hard Choices,” IMF Blog, April 8, 2026, https://www.imf.org/en/blogs/articles/2026/04/08/wars-impose-lasting-economic-costs-while-more-defense-spending-means-hard-choices.

¹⁶ Sarah Ferris et al., “Cracks Emerge in GOP Over Iran War Cost as Administration Floats More Than $200B Request to Congress,” CNN, March 19, 2026, https://edition.cnn.com/2026/03/19/politics/iran-war-cost-republicans-congress.

¹⁷ Center for Strategic and International Studies, “Iran Conflict Heightens Cyber Threats to U.S. Energy Infrastructure,” April 2026, https://www.csis.org/analysis/iran-conflict-heightens-cyber-threats-us-energy-infrastructure.

¹⁸ International Monetary Fund, “Wars Impose Lasting Economic Costs, While More Defense Spending Means Hard Choices.”