Extended Abstract

Introduction

The containment of the Islamic Republic of Iran has consistently been one of the enduring pillars of United States foreign policy in the post-Cold War international order. Nevertheless, the presidency of Donald Trump represents a distinctive and less-explored pattern in this regard compared to previous administrations. What sets Trump's policy apart is not merely the intensification of sanctions or withdrawal from the JCPOA, but a specific combination of two classical realist mechanisms: buck-passing and offshore balancing. While most existing literature reduces Trump's foreign policy to personality traits, populism, or decision-making volatility, this article seeks to provide a systematic explanation of Trump's logic toward Iran within the framework of structural realism. The central puzzle is what strategic pattern the Trump administration employed to contain Iran and how this pattern evolved under the influence of specific variables.

Research Question

The main research question is: What fundamental strategic difference does Donald Trump's policy for containing Iran have compared to previous U.S. administrations, and how and why did this policy move from an initial emphasis on buck-passing toward active offshore balancing?

More precisely, the article seeks to demonstrate whether the shift in Trump's policy was merely a result of episodic and personal fluctuations or follows a pragmatic, cost-sensitive realist logic in which the relationship between buck-passing and offshore balancing is dynamically and contingently readjusted.

Hypothesis

The main hypothesis argues that the Trump administration, within a pragmatic and cost-sensitive realism, pursued a hybrid containment strategy consisting of two distinct but complementary phases. In the first phase, buck-passing to regional allies (particularly Saudi Arabia, Israel, and the Gulf Cooperation Council states) was chosen as the lower-cost and preferred option. However, the ineffectiveness of these allies in establishing sustainable deterrence against Iran, coupled with escalating regional security threats, gradually pushed the Trump administration toward activating the offshore balancing mechanism. Nevertheless, this transition did not mean the complete abandonment of buck-passing but rather produced a dynamic combination of both mechanisms. In other words, what is observed in Trump's policy toward Iran is not a choice between two contradictory strategies but a contingent adjustment of their ratio based on the effectiveness of each mechanism in threat management and cost reduction for the hegemon.

Results and Discussion

In its discussion section, drawing on reliable documentary data including official U.S. government documents, Congressional reports, the 2025 National Security Strategy, and primary academic sources, the article presents three key findings.

First, the article demonstrates that buck-passing under the Trump administration was not merely a political slogan but was pursued through three specific implementation mechanisms. These included encouraging the normalisation of Israeli-Arab relations through the Abraham Accords to form a united anti-Iran front; large-scale advanced arms sales to Saudi Arabia (including a $110 billion agreement in 2017 and $600 billion in agreements in 2025), Gulf Cooperation Council states, and Israel (which has sourced 78 percent of its arms imports from the U.S. since 2000); and designing a maximum pressure campaign in such a way that the primary burden of sanctions fell on Iran while the implementation costs were delegated as much as possible to international institutions and regional allies. However, the data presented in the article show that these mechanisms alone failed to create sustainable deterrence.

Second, the article analyses the strategic transition to offshore balancing and identifies four main factors that drove this transition. These were the failure of regional actors to contain Iran, as clearly evidenced by attacks on Aramco, the attack on the U.S. embassy in Baghdad, maritime attacks in the Bab el-Mandeb, and operations True Promise One and Two; the resumption of Saudi-Iranian relations, which weakened the unified anti-Iran front; the halt in the normalisation of Arab-Israeli relations due to the Gaza war; and the increased level of conventional and asymmetric threats from Iran, which rendered buck-passing ineffective. In response to this ineffectiveness, the Trump administration activated four offshore balancing mechanisms: escalating sanctions and the revival of the maximum pressure campaign, including the activation of the snapback mechanism in the UN Security Council; the asymmetric and targeted assassination of Qasem Soleimani on 3 January 2020; a direct but limited military buildup in the Persian Gulf, including the deployment of 15,000 troops in 2019 and an increase in total U.S. forces in the region to approximately 50,000 by late 2024; and entry into direct but controlled warfare through Operation Midnight Hammer in June 2025, during which the nuclear facilities at Fordow, Natanz, and Isfahan were targeted.

Third, the article argues theoretically that buck-passing and offshore balancing are not two contradictory strategies but rather two levels of a single strategic hierarchy. In this framework, buck-passing operates as the first stage of containment, which is inherently fragile and conditional on the capability of allies. Whenever this condition is not met, offshore balancing is activated as the ultimate tool of equilibrium maintenance. This theoretical innovation helps explain the dynamics of U.S. foreign policy toward Iran and demonstrates that Trump's approach reflects not confusion but strategic flexibility.

Conclusion

The article reaches several central conclusions. First, Donald Trump's policy toward Iran should be understood as the embodiment of a constrained offensive realism in which buck-passing remains the preferred option, but the moment this mechanism fails, offshore balancing is activated without hesitation. Second, this hybrid pattern is likely to become entrenched in future U.S. foreign policy, particularly in regions where local actors cannot secure the hegemon's interests, where limited and direct intervention will be seen not only as possible but necessary (as the Venezuela case and the abduction of Nicolás Maduro have shown). Third, the implication of this strategy for the future of Middle East security will be neither lasting peace nor all-out war, but rather a pattern of controlled tensions, limited strikes, and unstable mutual deterrence, unless Trump becomes convinced that the very existence of the Islamic Republic poses an imminent and serious threat to U.S. interests, in which case a large-scale attack would be prepared. At the theoretical level, by presenting a hybrid model of buck-passing and offshore balancing, the article contributes to the development of structural realism literature and shows that these two mechanisms are not contradictory but function as complementary components of an effective containment strategy. Finally, the article emphasises that the future of Iran-U.S. relations will be shaped not by trust or normative agreements, but by the perpetual calculation of power, cost, and deterrence.