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The Conditions of a “Model Ally” |
| April 1, 2026 |
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Bee Yun JOResearch Fellow, Sejong Institute | bjo87@sejong.org
Sungwon LEEResearch Fellow, Sejong Institute | sw.lee@sejong.org -
The U.S.–Israeli conflict with Iran, erupted on February 28, 2026, calls for a reconsideration of what the Trump administration means by a “Model Ally.” The 2026 National Defense Strategy (NDS) characterizes Israel as a representative example of such an ally, one that possesses both the will and the capability to defend itself even under what the United States describes as “critical but more limited support.”1)
The 2026 NDS also devotes significant attention to Operation Midnight Hammer, the June 2025 strikes in which seven B-2 bombers targeted three Iranian nuclear facilities at Fordow, Natanz, and Isfahan, describing it as an example of U.S.‘s “critical support.” In this sense, the recent U.S.–Israel military operation offers significant implications for what the Trump administration considers the conditions of a model ally, and what “critical but more limited support” looks like in practice.
Yet this is precisely where a deeper question emerges. An ally that possesses the will and capability to fight on its own may closely resemble the kind of partner the Trump administration favors. Whether such an ally consistently advances U.S. national interests and the “America First” agenda, however, remains an open question. The more burdens an ally assumes, the more it can reduce the United States’ immediate strategic obligations. At the same time, however, a capable and proactive ally may also increase the risk of entrapment, escalation, and political costs that Washington did not intend to bear.
This paper begins from here. Drawing on the 2026 NDS, it first identifies the conditions that define a model ally under the Trump administration’s framework. It then examines the U.S.–Israeli military operation against Iran in light of these conditions. It further explores the biases and limitations of the Trump administration’s conception of alliances through European allies’ responses, before deriving implications for the ROK–U.S. alliance, which is also frequently cited as another “model ally.” -
As noted above, what the Trump administration refers to as a “model ally” differs from the traditional notion of a friendly ally or one that shares values with the United States. As the 2026 National Defense Strategy (NDS) makes clear, the United States, while placing greater emphasis on homeland defense and the Indo-Pacific, calls on its allies and partners to assume “primary responsibility” for addressing the threats they face. Within this framework, the United States envisions providing “critical but more limited support” on the premise that its allies possess both the will and the capability to defend themselves.2)
In this sense, a model ally in the Trump administration’s view is not one that is defended by the United States, but one that can deter conflict and respond to crises even with more limited U.S. support.
Unpacking this concept yields at least three distinct conditions. The first is the will and capability to defend itself. Will matters as much as capability. The NDS singles out Israel not merely because of its military strength, but because it is an ally prepared to fight before the United States enters a crisis. The same logic appears in the NDS’s assessment of South Korea, which states that it can assume “primary responsibility for deterring North Korea on the basis of strong military power, high defense spending, defense industrial capacity, and a conscript military.” 3) In the Trump administration’s conception of alliances, a good ally is not one that shelters comfortably under the U.S. security umbrella, but one that assumes primary responsibility for its own defense.
The second condition is burden-sharing and substantive investment. The 2026 NDS criticizes the extent to which many allies have grown accustomed to the United States effectively subsidizing their defense, resulting in partners that are “more akin to dependents than allies.”4) It further acknowledges that U.S. policymakers themselves helped sustain this pattern and calls on allies to carry “their fair share of the burden” in collective defense. This logic was echoed shortly after the release of the 2026 NDS, when Elbridge Colby, Under Secretary of War for Policy, stated during a public address at the Sejong Institute that alliances must rest on “aligned interests, shared risk, proportionate contributions, and mutual benefit.” It was on precisely these grounds that he described South Korea as “a model ally.”5)
The third condition is alignment with U.S. grand strategy. The Trump administration’s model ally is not simply a strong partner in its own right, but one whose strength enables U.S. grand strategy. The 2026 NDS argues that the more allies in Europe, the Middle East, and on the Korean Peninsula assume primary responsibility for their own defense, the more the United States can concentrate on homeland defense and countering China. A “model ally” is therefore defined not by defense spending alone, but by playing a visibly greater role “in their regions” 6) and reducing the United States’ strategic burden through weapons procurement, defense industrial collaboration, and intelligence sharing. In other words, a Trump-style model ally is best understood as a strategic asset that makes “America First” possible.
In sum, there are three conditions to the Trump administration’s model ally: the will and capability to defend itself; to assume greater costs and responsibilities; and the ability to play a substantive role in its region in line with U.S. strategic priorities. Seen in this light, the conditions of a “good ally” are considerably more cold-eyed and transactional than the language of traditional values-based alliance suggests. Above all, it describes an ally that helps preserve U.S. power, attention, and strategic bandwidth. -
The U.S.–Israeli military operation against Iran can be seen as a prime example of how the conditions of a model ally translate into practice on the battlefield. Its most symbolic illustration is Operation Midnight Hammer in June 2025. According to the U.S. Department of War, the operation deployed seven B-2 stealth bombers, fourteen GBU-57 Massive Ordnance Penetrators (MOPs), more than twenty-four Tomahawk cruise missiles, approximately seventy-five precision-guided munitions, and over 125 U.S. aircraft, targeting three nuclear facilities at Fordow, Natanz, and Isfahan. Deeply buried installations such as Fordow were targets that Israel alone could not strike with assured effect, and it was precisely in this respect that U.S. involvement was not merely supplementary but genuinely critical. At the same time, the operation’s focus on a limited set of deep strikes against specific high-priority facilities, rather than the conduct of full-scale war, illustrates what the Trump administration means by “limited” support. The United States did not prosecute the war on Israel’s behalf; rather, it deployed overwhelming capability only in those critical areas beyond the ally’s independent reach. The operation thus represents a near-textbook case of “critical but more limited support.”
The ongoing 2026 U.S.–Israeli war on Iran reflects a similar division of labor. Now in its fourth week since hostilities began on February 28, Israel has continued to conduct airstrikes on military, intelligence, and missile-related facilities across Iran and in Tehran. The United States, meanwhile, has not prosecuted the war on Israel’s behalf but has intervened in accordance with its own defined war objectives. While inconsistent messages from Trump, including references to regime change in Iran, have introduced uncertainty regarding the war’s objectives, Secretary of War Pete Hegseth, Chairman of the Joint Chiefs General Dan Caine, and Central Command Commander Admiral Brad Cooper have presented a relatively consistent set of objectives for Operation Epic Fury in press briefings: the elimination and neutralization of Iran’s ballistic missile capabilities, including production capacity, the degradation of its naval capabilities, and the prevention of Iran’s acquisition of nuclear weapons.7) This suggests that the United States views the war primarily as an effort to eliminate Iran’s strategic threats, namely its missile, naval, and nuclear capabilities that can inflict harms to U.S. homeland. Within this division of labor, Israel plays the role of opening and sustaining the battlefield at the front, while the United States concentrates on deep strikes beyond Israel’s independent reach, strategic deterrence, management of sea lines of communication (SLOC), and securing a diplomatic off-ramp. In other words, while Israel leads at the tactical and operational level, the United States intervenes by supporting the strategic tier that governs the war’s objectives and escalation management.
The problem, however, is that what currently appears to be “critical but more limited support” may in fact be deepening U.S. entrapment over time. Iran has recently launched long-range ballistic missiles targeting the vicinity of Dimona, the linchpin of Israel’s nuclear program,8) signaling that the battlefield is expanding toward Israel’s nuclear-related infrastructure. At the same time, after President Trump publicly raised the possibility of striking Iran’s power infrastructure to pressure Tehran into reopening the Strait of Hormuz, the Islamic Revolutionary Guard Corps (IRGC) warned that not only Israeli power plants but also facilities supplying electricity to U.S. military bases in the region could become targets for retaliation.9) With discussion now extending to possible Iranian strikes on desalination infrastructure, the conflict has moved well beyond a bilateral Israel–Iran confrontation toward a trajectory that could destabilize the broader Gulf region’s energy, power, and water supply systems. What the United States originally conceived as “critical but limited support” is thus expanding into a far wider set of commitments: defense of SLOC in the Middle East, protection of in-theater bases, securing allied critical infrastructure, and stabilizing international energy markets. All of this prompts the question of whether the current war is not relieving the United States of its burdens, but rather drawing it ever deeper into entrapment by the very assertiveness of its model ally and the escalating breadth of the battlefield.
These two cases clearly reveal what a model ally truly entails. First, a model ally is not one for which the United States fights, but one with the will and capability to fight first. Second, it is an ally willing to bear a greater share of real costs and risks. Third, it is not simply a pro-American ally, but functionally aligned with and supportive of U.S. grand strategy. Yet it is precisely these qualities that also expose the concept’s limitations. The stronger and more autonomous an ally becomes, the more it may relieve the United States’ burdens, but also the greater the risk that it will draw Washington into escalation and political costs it did not seek. As both Operation Midnight Hammer and the ongoing Operation Epic Fury have shown, overwhelming deep strikes may be militarily critical and decisive, but they do not guarantee an end to the war. The central question, ultimately, is what the United States stands to gain from this war. It may succeed in degrading Iran’s nuclear, missile, and naval threats, but the question arises whether the United States is not becoming more deeply entrapped in the very war its model ally was supposed to help it avoid. The military operation against Iran thus reveals not only the utility of a model ally, but the paradox by which that very utility draws the United States back into a protracted war of attrition in the Middle East. -
The concept of alliance under the second Trump administration is thus undergoing a fundamental recalibration. The traditional notion of alliance as a defense community grounded in “shared values” is being recast as a more transactional arrangement, in which an ally’s worth is measured by “performance indicators,” namely the degree to which it aligns with the security patron’s defined national interests and the level of contribution it is willing to make. Assessed against these performance indicators, Israel has been recognized as a “model ally,” satisfying all of the relevant conditions: a high degree of policy alignment with U.S. foreign strategy, deep defense (weapons) integration with the United States, and the assumption of primary responsibility for regional deterrence through burden-sharing and proven operational capacity.
By contrast, the transatlantic alliance between North America and Europe, long one of the central pillars in the design and maintenance of the postwar security order, is exhibiting significant fractures. The NDS published in January gives unvarnished expression to the second Trump administration’s distrust and frustration with Europe and NATO. The core of the criticism centers on Europe’s perceived overestimation of the Russian threat, its low level of autonomous defense capability and dependence on the United States for security, and its limited contributions to U.S.-led responses to international challenges, all of which point to deeply embedded irrationalities and asymmetries in the alliance relationship. In particular, the diplomatic and military tensions surrounding U.S. attempts to incorporate Greenland into American territory stand out as a prime example of how far transatlantic fractures have deepened.
Europe’s Perception of and Stance Toward the Iran War
The U.S.–Israeli-led strikes on Iran and the current Middle East war have offered a stark illustration of the subtle divergence between American and European visions of alliance, and the ambivalence Europe displays as an ally. Europe’s reading of the Iran war is far from simple. From Europe’s perspective, the war is perceived as one that is “unwanted, unchosen, and beyond its control.” European opinion has coalesced around a posture of cautious neutrality, oscillating between defensive support and declaratory solidarity without firmly committing to either. From a security standpoint, instability in the Middle East and the nuclear threat have long been perceived as latent concerns for Europe.10) However, with European defense assets and budgets already stretched to their limits in managing the Russia-Ukraine war on the eastern front, Europe has precious little capacity to address the Middle East threat as well.
The macro-level objectives the United States has set out, namely regime change in Iran and the elimination of nuclear and missile threats, could, if ultimately achieved, leave room for a favorable interpretation from Europe’s perspective. Guided by this strategic calculus, senior NATO and EU officials signaled at the outset of the war that Europe and the United States stood on the same side. In practice, however, the collateral costs of involvement in a conflict with an uncertain outcome weigh more heavily on Europe than the prospect of indirect gains. Escalation in the Middle East could directly affect European energy supplies, maritime trade, and inflation, and, perhaps most critically, any diversion of defense assets from the eastern front risks deepening Europe’s multiple vulnerabilities.
The risks of involvement are high, while the justification remains thin. The United States and Israel launched a large-scale military operation without prior close consultation with Europe, and subsequently sought to draw Europe into involuntary involvement. The United States requested the use of military bases on the territory of certain EU and NATO member states, and while some agreed to do so, they drew a clear line by limiting their use to defensive purposes and refraining from direct participation in the war. Subsequent U.S. requests for support in military operations to lift the Strait of Hormuz blockade were likewise rebuffed, with European governments declining to deploy military assets or troops. From the outset of the war to the present, Europe has consistently maintained a neutral and measured posture, grounding its position in the principles of maximum restraint, respect for international law, diplomatic resolution, and regional stability.
Europe: Bystander or Stabilizer?
President Trump has repeatedly expressed disappointment and frustration with Europe’s ambivalent stance, wanting the secondary benefits of victory while stopping short of sharing in the direct risks. He has specifically dismissed Europe’s refusal to participate militarily in the Strait of Hormuz as a deeply misguided decision, and argued that Europe’s behavior could have served as a test of whether NATO’s collective defense is capable of functioning in any meaningful sense.
Europe’s dilemma is clear: how to balance alliance solidarity with the United States against the defense of international norms and order. On the surface, Europe falls short of the model ally criteria the Trump administration has set out. As noted above, Europe currently identifies Russia as its most acute existential threat and has set support for Ukraine and the strengthening of the eastern front as its foremost security priorities. As the United States has scaled back its defense commitments in Europe, Europe announced its Readiness 2030 rearmament plan in 2025, pursuing a range of initiatives to promote European-centered defense technology development, expand weapons production capacity, and enhance integrated deterrence and operational capabilities. The reality, however, tells a different story. Prolonged war fatigue among member states, domestic political resistance to defense budget increases, and a sluggishly growing European economy have combined to constrain both the collective will to strengthen deterrence and the capacity to do so. Europe thus finds itself woefully short of the capacity to engage in the current Middle East conflict. Europe simply lacks the political, economic, and military will to take on yet another front to the south. Sharing American convictions while refusing to share American risks is, in plain terms, a form of free-riding. In Trump’s terms, a Europe that is all talk and no action risks being seen as a bandwagoning ally.
Yet it is worth pausing to consider whether failing to meet Trump’s model ally criteria necessarily makes Europe detrimental to the United States. Since the outbreak of the current Middle East conflict, Europe has consistently and collectively condemned Iran’s asymmetric retaliation against neighboring states and its maritime blockade, and has pressed for diplomatic solutions aimed at energy stability, the protection of civilian infrastructure, safe passage at sea, and the prevention of unnecessary escalation.
With no clear exit strategy in sight, the United States is showing signs of internal division, shifting primary responsibility for the war onto Israel. Despite high levels of operational integration at the military level, Israel has demonstrated misalignment with the United States on the war’s ultimate objectives, its conduct, and its exit strategy, in ways that have, to some extent, deepened rather than alleviated U.S. entrapment. Europe, by contrast, has declined to defer unconditionally to U.S. decisions, instead scrutinizing the normative legitimacy of its own potential involvement, weighing the costs of over-escalation, and conservatively calibrating its threshold for military engagement, thereby performing the function of a stabilizer oriented toward preventing horizontal escalation and minimizing U.S. entrapment. This role is categorically distinct from that of an ally participating in the conduct of war. The scope of alliance cannot be reduced to military partnership in threat response and warfighting alone. Burden-sharing is one function of an alliance, not the whole of its mechanism. Equally important as helping an ally win a war is the stabilizer’s role of reinforcing normative legitimacy, managing conflict, and preventing an ally from becoming unnecessarily entrapped. -
The current Iran war reveals the tensions at the heart of the Trump administration’s concept of a model ally. Gauged against the administration’s own standards of flexible realism—clarity of priorities, disciplined commitments, decisiveness in execution, and prudence in deterrence—Israel has demonstrated decisiveness through close threat alignment with the United States and sustained high-intensity military action. Yet those same qualities have also complicated America’s position. Rather than easing U.S. burdens, Israel’s conduct has clouded Washington’s path to a war exit, increased its military, political, and economic exposure, blurred the hierarchy of U.S. strategic priorities, and weakened the prudence of its deterrence posture. Europe, by contrast, declined to join the war directly as a belligerent. Even so, it has sought to constrain the conflict through normative and diplomatic frameworks centered on international law, de-escalation, and freedom of navigation, thereby indirectly reducing U.S. strategic burdens, broadening the normative basis for a war exit, and limiting moral hazard within the alliance.
The broader lesson for the U.S.-led alliance order is clear. A model ally cannot be defined simply by which partner is more loyal or more willing to fight. No less important than helping an ally prevail in war is the capacity to sustain cooperation within the bounds of national priorities, reinforce normative legitimacy, and prevent unnecessary entrapment in a widening conflict.
The policy implications for the ROK–U.S. alliance are equally significant. First, as the Iran war continues to unfold, a model ally will be increasingly difficult to define as simply one that responds more readily to U.S. requests and goes further alongside Washington. What matters is the capacity to substantively reduce U.S. strategic burdens while preventing the alliance from being automatically drawn into unnecessary wars and escalation. Put differently, the value of an ally must be assessed not only in terms of “contribution” but also in terms of “calibration.” The roles necessary for deterrence must be performed, but that contribution must not automatically translate into unlimited military intervention or unconditional strategic alignment.
Second, for the ROK–U.S. alliance to become a model ally capable of both “contribution” and “calibration,” predictable principles and consistent judgment will be required. South Korea already stands close to what the United States considers the “model ally of Asia,” built on high defense spending, strong conventional forces, a strong defense industrial capacity, and deep interoperability with U.S. Forces Korea. Yet Seoul should resist becoming captive to the label itself. Instead, it must establish clear criteria for where cooperation should extend and where it should stop in any given case. Alliance credibility does not rest on unconditional compliance.
Third, in out-of-area crises such as the situation in the Strait of Hormuz, South Korea’s role should not be that of “an ally that goes along with everything,” but one that “makes clear what it can do” in light of its national interests and strategic priorities. South Korea could, for example, actively participate in joint ROK–U.S.and/or multilateral statements emphasizing freedom of navigation, the safety of SLOC, energy supply security, and the protection of civilian infrastructure. It can also play a meaningful role in non-military and diplomatic dimensions, including intelligence-sharing, situational assessment, non-combat cooperation for vessel protection, and signaling on energy market stability. Such solidarity, however, should not automatically translate into military deployment or participation in combat operations. Questions such as deployment to the Strait of Hormuz require careful deliberation that weighs South Korea’s direct national interests, the scope and objectives of the mission, its international legal basis, the risks of escalation, and the impact on readiness on the Korean Peninsula. In particular, given deepening U.S. entrapment in the Middle East and North Korea’s continuing advances in nuclear and missile capabilities, including drones sharpened through its involvement in the Russia–Ukraine war, South Korea must be clear about which front it prioritizes.
The Iran war has shown that an alliance today cannot rest on the ability to fight together alone. It must be able to contribute to deterrence, but it must equally be able to prevent unnecessary entrapment, preserve strategic priorities, and widen diplomatic off-ramps. For the ROK–U.S. alliance to remain a stable and sustainable “model ally” going forward, it must move beyond simply saying yes or no to U.S. demands, and instead strike a balance between substantive contribution and strategic restraint, between military solidarity and normative calibration.
I. Introduction
II. The Conditions of a Model Ally
III. The U.S.–Israeli Military Operation Against Iran and the Conditions of a Model Ally
IV. Europe, Not a Model Ally?
V. Conclusion
1) US Department of War. (2026). 2026 National Defense Strategy, p. 2.
2) Ibid., p. 14.
3) Ibid., p. 20.
4) Ibid., p. 4.
5) US Department of War. (2026. 1. 26.). “Remarks by Under Secretary of War for Policy Elbridge Colby at the Sejong Institute in South Korea (As Delivered).”
6) US Department of War. (2026). 2026 National Defense Strategy, p. 19.
7) US Department of War. (2026. 3. 19.). “Secretary of War Pete Hegseth and Chairman of the Joint Chiefs Air Force Gen. Dan Caine Hold a Press Briefing.”; Video updates from Admiral Cooper are also regularly posted on U.S. Central Command’s official X account.
8) Aljazeera. (2026. 3. 22.). “Aftermath of Iranian missile strikes near Israel’s nuclear facility.”
9) Reuters. (2026. 3. 23.). “Iran points at tit for tat retaliation if power plants targeted, statement.”
10) For example, a 2025 threat perception survey conducted by the Robert Schuman Centre for Advanced Studies (EUI-RSC) in collaboration with the European Union Institute for Security Studies (EUISS), the Trans-European Policy Studies Association (TEPSA), and the European Initiative for Security Studies (EISS), involving approximately 400 European foreign and security policy experts, found that the Iran-Hamas and Iran-Israel conflicts were classified among Europe’s top ten global risks and categorized as high-risk threats.
※ The contents published on 'Sejong Focus' are personal opinions of the author and do not represent the official views of Sejong Institue
