INVESTIGATION: The Senate refuses to rein in Trump on Iran — war powers at the heart of a late-night vote

Introduction: A night at the Capitol that redefines American war powers

The vote that did not constrain Trump

On the night of June 25, 2026, the American Senate rejected the war powers resolution concerning Iran. That late-night vote, at the end of a day of tensions between the White House and its own Republican allies, confirmed something fundamental: Donald Trump retains virtually unlimited war powers over Iran without requiring the formal approval of the United States Congress. A result that redefines the constitutional balance between the executive and the legislature in the conduct of American wars.

This vote took place in a context that is anything but hypothetical. The war between the United States and Iran began on February 28, 2026. At the time of the vote, it had been ongoing for more than 106 days. This is not a theoretical debate about abstract war powers — it is a real conflict, with deployed soldiers, ongoing military operations, and geopolitical consequences resonating across the entire Middle East region and beyond.

Before the vote: an explosive lunch at the Capitol

The hours preceding the vote revealed the intensity of the tensions within the Republican Party. Trump directly confronted dissident Republican senators at a Capitol lunch, just hours before the late-night vote. These senators, who believed that Congress should reclaim its constitutional role in declaring and conducting wars, found themselves face to face with a president fiercely defending his executive prerogatives.

The pressure applied during that lunch — the precise details of which trickled out slowly through Washington media — illustrates the Trump method: direct, personal confrontation with his own allies to ensure their loyalty on a crucial vote. That method works, as the vote outcome demonstrates. But it leaves marks on the relationship between the president and the segment of his party that believes the constitutional balance of powers deserves to be defended.

The War Powers Resolution: history and constitutional stakes

A 1973 text consistently circumvented

The war powers resolution that was rejected falls within the framework of the War Powers Resolution of 1973, adopted after Vietnam to compel American presidents to consult Congress before committing armed forces to prolonged conflicts. That text provides that the president must notify Congress within 48 hours of committing armed forces, and that such commitment cannot exceed 60 days without legislative authorization.

Since 1973, virtually every American president has circumvented or ignored this law, asserting that their constitutional powers as commander in chief allow them to engage in military operations without prior congressional approval. Trump is no exception, and his refusal to submit to legislative oversight on the war against Iran fits squarely within this long tradition of expanding executive prerogatives in military matters.

The specific nature of the Iran-USA conflict of 2026

But the context of 2026 is different in several respects. The direct war between the United States and Iran, triggered on February 28, 2026, represents a conflict of a different scale and nature from recent American interventions in Syria, Libya, or Yemen. This is not a matter of pinpoint strikes against non-state groups or support operations for allied forces. It is a direct confrontation between two nation-states, with all the implications that entails for regional stability and international security.

The duration of the conflict — more than 106 days at the time of the vote — also raises practical questions about its conduct and objectives. A war lasting more than three months without formal congressional authorization represents precisely the type of situation that the War Powers Resolution of 1973 was intended to prevent. The Senate's refusal to remind the president of this constitutional obligation speaks volumes about the evolution of relations between the two branches under the Trump era.

The defense sector in overdrive: $12.3 billion in venture capital in six months

Unprecedented attractiveness for defense investors

Alongside these constitutional stakes, the financial context of the defense sector in 2026 reveals a profound transformation in the funding of the American military industry. According to data available as of June 2026, global venture capital investors poured $12.3 billion into defense startups in the first half of 2026 alone. By comparison, the entirety of 2025 saw $9.95 billion invested in that sector.

This spectacular acceleration reflects a paradigm shift in how investors perceive the defense sector. The Iran-USA war, tensions with China, the war in Ukraine, and the proliferation of regional conflicts have transformed defense technology into an attractive investment sector for venture capital, which had previously been reluctant to engage in this space for ethical or regulatory complexity reasons.

Anduril Industries and the new privatization model of defense

The most emblematic example of this trend is Anduril Industries, the defense startup founded by Palmer Luckey. In March 2026, Anduril secured a $20 billion contract with the American military for anti-drone systems. This colossal contract illustrates the progressive shift of American military procurement toward agile private technology companies, at the expense of large traditional Pentagon contractors.

This model of defense privatization raises fundamental questions about the nature of the American military-industrial complex in the 21st century. When a Silicon Valley startup obtains a $20 billion contract to equip the American armed forces, it acquires considerable institutional and political influence. The alignment between the commercial interests of defense technology companies and Washington's geopolitical decisions warrants careful critical scrutiny.

The Republican dissidents: who are the senators who defied Trump?

A constitutionalist minority within the GOP

The war powers resolution could not have been debated in the Senate without the support of at least a few Republican senators willing to defy their own president. This constitutionalist minority within the Republican Party represents a political current that believes congressional prerogatives — particularly on the declaration of war — are non-negotiable, regardless of the confidence placed in the chief executive.

These senators are not necessarily anti-Trump on the substance of Iran policy. Some support a firm approach toward Tehran. But they believe that the form — military engagement without a formal congressional authorization vote — represents an unacceptable institutional precedent whose consequences will be felt long after the current conflict ends. Their argument is constitutional, not partisan.

After the Capitol lunch: the majority falls in line

But after the Capitol lunch with Trump, the majority of wavering Republican senators rallied to the presidential position. That rally illustrates the power of the Trumpian pressure apparatus on its own congressional allies. Constitutional arguments, however sound, struggle to withstand the combination of personal presidential pressure, the implicit threat of a punitive primary, and group dynamics within a Republican caucus largely aligned with Trump.

The final result — the rejection of the resolution and Trump's political victory — is a short-term win for the White House. But it is also a signal to future presidents, of whatever political stripe, that they can engage in wars without meaningful legislative constraint. It is a major constitutional precedent that deserves far deeper analysis than a simple partisan scorecard of the moment.

The Vance-Iran talks in Geneva: a de-escalation under way?

Vance in Switzerland: the inside story of a discreet diplomacy

While the Senate debated the war powers resolution, Vice President J.D. Vance was engaged in high-stakes talks in Switzerland on June 22, 2026, with Iranian officials. These discussions, reported by NPR, testify to an effort by the Trump administration to manage an exit from the conflict while maintaining a position of strength.

The simultaneous occurrence of quiet diplomatic talks in Switzerland and a Senate vote on war powers creates a significant narrative dissonance. On one hand, the Trump administration tells its Republican allies it needs all the military flexibility possible to manage Iran. On the other, Vance is negotiating in Geneva hoping to find a de-escalation. These two dynamics are not mutually exclusive — pressure diplomacy and negotiation can coexist — but they complicate the political reading of the moment.

New negotiations in Geneva: is a deal possible?

Reports from Aletihad dated June 21, 2026 indicated that the United States and Iran are preparing for new negotiations in Geneva. The existence of these negotiations confirms that, despite 106 days of war, both parties are seeking a diplomatic exit. The stakes of these negotiations are considerable: they touch not only on the Iranian nuclear program, but also on questions of compensation, sanctions relief, and the redefinition of the balance of power in the Gulf region.

The economic impact of a potential deal with Iran was already visible in Goldman Sachs's revised petroleum forecasts, which lowered its fourth-quarter 2026 Brent crude price outlook from $90 to $80 per barrel. An Iranian de-escalation would ease pressure on global energy prices, with positive ripple effects on energy-importing Western economies.

The defense sector and private investment: a structural transformation

From the traditional Pentagon to technology startups

The transformation of the American defense sector is deep and structural. The $12.3 billion invested by global venture capital in defense startups in the first half of 2026 does not represent merely a cyclical anomaly linked to the wartime context. They reflect a paradigm shift in the way America conceives, develops, and procures its military capabilities.

The large traditional defense companies — Lockheed Martin, Raytheon, Northrop Grumman — are confronted with the rise of agile technology challengers like Anduril, Palantir, Shield AI, and Joby Aviation. These new entrants benefit from an accelerated innovation culture inherited from Silicon Valley, shorter development cycles, and an ability to attract top engineers who sometimes flee the traditional organizations of the defense sector.

The implications for American military doctrine

This shift toward defense technology startups is not without consequences for American military doctrine. The emphasis on anti-drone systems (the Anduril contract), artificial intelligence applied to the battlefield, autonomous systems, and electronic warfare reflects a vision of future warfare very different from the conventional conflicts of the 20th century.

The war in Ukraine has been the laboratory for this vision: FPV drones, multi-layered air defense systems, information warfare, and intensive electronic warfare have dominated the fighting. The American military is drawing lessons from that conflict to modernize its own capabilities. The Anduril contract for $20 billion for anti-drone systems is a direct illustration. The challenge is to maintain technological superiority over adversaries — China, Russia, Iran, North Korea — that are also investing heavily in these technologies.

The legal context: the constitutionality of presidential war powers

The doctrinal debate between the executive and the legislature

The battle over the war powers resolution is rooted in a constitutional debate that is 230 years old. The American Constitution divides war powers between Congress — which alone can declare war and allocate military funds — and the president — who serves as commander in chief of the armed forces. This division has always created tensions during conflicts, with each branch tending to maximize its prerogatives at the other's expense.

The historical trend since World War II is clear: American presidents have progressively expanded their war powers at the expense of Congress. The last formal declaration of war by the United States Congress dates to 1942. Since then, all major American conflicts — Korea, Vietnam, Gulf, Iraq, Afghanistan — have been conducted without a formal declaration of war, with only authorizations for the use of force or solely presidential authority.

Iran as a test case for the doctrine

The war against Iran in 2026 represents a particularly revealing test case for this doctrine of executive powers in military matters. Trump invokes his constitutional powers as commander in chief and, presumably, post-September 11 laws such as the AUMF (Authorization for Use of Military Force) to justify military engagement without a formal Congress vote.

But constitutional experts argue that Iran was not involved in the September 11 attacks and that using the AUMF to justify a war against Tehran represents an abusive extension of that text. The Senate's rejection of the war powers resolution means this legal question will not be resolved through the legislative route. It could be resolved judicially — if organizations or elected officials take the matter to court to challenge the constitutionality of how this war is being conducted.

Washington's allies facing the Iran-USA war

Gulf partners caught between two stools

The war between the United States and Iran has placed Washington's regional partners in positions of extraordinary complexity. The Persian Gulf monarchies — Saudi Arabia, the United Arab Emirates, Qatar, Bahrain — maintain close security ties with the United States while also maintaining economic and sometimes political ties with Iran. Geography makes them vulnerable to Iranian reprisals.

These Gulf states sought to stay out of the conflict while maintaining their American alliances. Some offered their territory for American logistical operations. Others played a discreet role in diplomatic channels. None chose direct military involvement alongside the United States. This caution reflects the complexity of the regional balances that the Arab Gulf partners must navigate.

Europe and its stake in regional stability

For Europe, the Iran-USA war represents both a risk and a major strategic issue. A risk because the destabilization of the Middle East directly affects migration flows, hydrocarbon supplies, and security in the Mediterranean. A strategic issue because the resolution of the Iranian nuclear conflict partly determines nuclear proliferation in an already volatile region.

Europeans were confronted with the fait accompli of the war's outbreak on February 28, 2026. Discussions with Washington on the war's timeline and objectives were tense. European partners would have preferred a longer diplomatic path. But faced with the reality of the conflict, they adapted, seeking to influence its modalities and resolution rather than oppose it head-on.

The implications for the long-term USA-Iran relationship

Toward a new regional balance of power

Whatever the outcome of the Geneva talks, the balance of power between the United States and Iran has been profoundly reconfigured by 106 days of direct war. Iran has demonstrated its capacity for resistance and its willingness not to collapse quickly under American military power. The United States has demonstrated its conventional military superiority but also the limits of a victory that is still searching for a political definition.

In this context, a Geneva agreement would not represent Tehran's capitulation or Washington's total victory. It would be a pragmatic arrangement between two powers that have each demonstrated their resilience and their limits. The question of the Iranian nuclear program, sanctions, American military presence in the region, and Iranian influence in neighboring Arab countries remain open files whose resolution will extend far beyond the scope of a single agreement.

The impacts on the arms race and defense investment

The Iran-USA war has also accelerated investment dynamics in defense that extend well beyond the directly involved actors. The $12.3 billion in venture capital invested in defense startups in the first half of 2026 partly reflects investors' anticipation of a more conflicted world — one in which defense technologies will be in growing, sustained demand.

This militarization of the global technology economy — with companies like Anduril, SpaceX/Starshield, Palantir, and their equivalents in Europe, Israel, and Asia — represents a long-term structural transformation. It is fueled not only by the Iran-USA conflict but also by the war in Ukraine, tensions in the South China Sea, and the proliferation of regional conflicts that make security a global investment priority.

The return of Congress: an institution under executive pressure

The erosion of Congress's role in military affairs

The rejection of the war powers resolution fits into a long-term trend: the erosion of Congress's role in American military decisions. Since the Korean War, Congress has progressively abdicated its constitutional prerogative to declare war, settling for Authorizations for Use of Military Force with deliberately broad language that leaves presidents near-unlimited latitude.

This progressive abdication has structural causes: modern wars break out rapidly, without time for a formal legislative process. Presidents have an interest in maximizing their freedom of action. Elected members of Congress often prefer not to take a position on conflicts that public opinion may turn against. The result is a constitutional drift that concentrates in the president's hands powers that the Founding Fathers deliberately wanted to share with the legislature.

Reforming the War Powers Resolution: necessary but unlikely

Constitutionalists and international law experts have for years argued the need to reform and strengthen the War Powers Resolution to make it a truly binding mechanism. Proposals have been put forward to require a formal authorization vote from Congress before any military engagement lasting more than 30 days, with automatic sanctions for non-compliance.

But these reforms run into a constant political reality: sitting presidents, of whatever political stripe, refuse to constrain their military prerogatives. And legislative majorities tend to support their own president's war decisions. The window for reforming this system typically only opens in moments of deep disillusionment following costly conflicts — as was the case for the War Powers Resolution of 1973, adopted in the wake of Vietnam.

Ukraine in the background: the forgotten war of the moment

Zelensky and the concern over a drift of attention

It would be incomplete to analyze the geopolitical context of June 2026 without mentioning what this American fixation on Iran means for Ukraine. Since the outbreak of the direct war between the United States and Iran, Ukraine and the heroic resistance of Volodymyr Zelensky have had to share American geopolitical and attentional space with a new front in the Gulf region.

This competition for Washington's strategic resources and attention legitimately concerns Kyiv. American military support for Ukraine has not collapsed, but the political and diplomatic energy devoted to Iran mobilizes actors and resources that, without this conflict, would have been entirely available for the Ukrainian file. Zelensky continues to fight with courage and determination, but he watches every Washington development with vigilance.

Putin and the opportunity of a divided America

On the Moscow side, the Iran-USA war is watched with a mixture of interested attention and unease. If American attention is split between the Ukrainian front and the Iranian front, Vladimir Putin might see in this division a tactical opportunity. But at the same time, an American victory against Iran would weaken one of Russia's circumstantial allies and strengthen American military credibility — which is not in Moscow's interest.

Russia has an interest in Iran holding on long enough to exhaust American resources and keep the United States bogged down in a Middle East conflict. But it has no interest in seeing Iran become a failed state or a state under direct American influence. This delicate balance partly explains Moscow's relative discretion on this conflict, which contrasts with its usual rhetorical activism.

The late-night vote as a signal to Washington's allies and adversaries

What the world took away from the Senate vote

The late-night vote of June 25, 2026 in the American Senate was watched closely by chancelleries around the world. By rejecting the war powers resolution, the Senate sent the world a message: the American president has all the freedom necessary to conduct military operations against Iran, without formal legislative constraint. This message is received differently depending on the capital.

In Tehran, this vote confirms that the American interlocutor in the Geneva negotiations is Trump alone, with the fullness of his executive powers. That simplifies the negotiation in one sense — you know who really decides — but it complicates it in another: does Trump's word durably bind the United States or can it be reversed by his successor? That question haunts every negotiation involving Washington since 2016.

A signal of strength but also of unilateralism

For Washington's allies — Europe, Japan, Australia, South Korea — this vote confirms a trend toward American military unilateralism that concerns capitals operating under their own constitutional and democratic constraints for committing armed forces. These allies must contend with an American partner that can trigger conflicts without prior deliberative process and then ask them for political and logistical support.

This asymmetry in decision-making processes — an America that decides alone, allies that adapt — is a source of structural tension within Western alliances. NATO and other multilateral alliance structures have consultation mechanisms, but they do not require the United States to obtain allied agreement before engaging in military operations in external theaters. The next crisis will test these mechanisms once again.

The institutional fracture: when Congress loses its voice before the executive

The progressive erosion of legislative checks and balances

Since the beginning of Donald Trump's second term, the United States Congress has faced a methodical erosion of its constitutional prerogatives. The vote of June 25, 2026 on the war powers resolution is not an isolated incident — it is the expression of a deep-seated trend. The War Powers Resolution of 1973, adopted precisely to counter presidential excesses after Vietnam, now finds itself neutralized by a disciplined Republican majority that chooses partisan loyalty over institutional oversight.

Constitutionalists observing this dynamic are sounding the alarm. When the United States Congress abdicates its power to declare war, it transfers to the executive an authority that the Founding Fathers deliberately distributed among the branches of government. The war against Iran, launched in February 2026 and still ongoing after 106 days, illustrates this drift in a striking fashion.

Dissident senators facing party pressure

The Republican senators who voted in favor of the resolution — against the White House's wishes — paid an immediate political price. In a Republican Party of 2026, voting against Trump exposes one to primaries, funding withdrawals, and social media attacks. This institutional courage is rare, which is why it deserves to be named. American democracy survives precisely because of these few rebel voices reminding us that the Senate is not a rubber-stamp chamber.

Internationally, these dissident votes are scrutinized by Washington's allies with particular attention. NATO, the European Union, and Pacific partners need to know that American democracy functions — that its institutions resist the concentration of power. The vote of June 25 sends an ambiguous signal: enough dissent to show the debate exists, but not enough to change the outcome.

The war economy and its winners: the military-industrial complex in full expansion

The $12.3 billion invested in defense in the first half of 2026

The number speaks for itself: $12.3 billion invested in the defense sector in the first half of 2026, compared to $9.95 billion for all of 2025. This spectacular acceleration in defense venture capital is not a product of chance — it is a direct reflection of a geopolitical situation in full boil. The war against Iran, persistent tensions with China in the South China Sea, and the continuing Russian threat in Europe create structural demand for military technologies.

Anduril Industries, which secured a $20 billion contract in March 2026, is the emblem of this new war economy. Founded by Silicon Valley entrepreneurs, funded by venture capital funds, Anduril represents the fusion of the technology world with the military complex. This model — agile, private, innovation-driven — is in the process of supplanting traditional defense giants like Lockheed Martin and Raytheon, which are slower and more bureaucratic.

The ethical and strategic implications of the privatization of war

But this transformation raises fundamental questions. When decisions about autonomous weapons systems, surveillance technologies, and combat drones are made by private companies motivated by profit, who ensures ethical oversight? The United States Congress, already weakened on questions of war powers, possesses the technical capacity to evaluate these systems? The evidence suggests not. The gap between the technological capabilities of the private sector and congressional understanding is abyssal.

For Washington's allies, the increasing privatization of American warfare is both an opportunity and a challenge. An opportunity, because technologies developed by companies like Anduril can be exported, shared, and integrated into allied defense systems. A challenge, because it creates commercial dependencies that complicate sovereign political decisions. Europe is learning this lesson painfully: its dependence on American defense technologies is a structural factor in its relations with Washington.

Conclusion: A presidential victory with lasting constitutional consequences

Trump won the vote, but at what institutional cost?

The rejection of the war powers resolution undeniably represents a short-term political victory for Donald Trump. He can continue to conduct the war against Iran without formal legislative constraint. He demonstrated his ability to maintain his Republican coalition in the Senate even on a sensitive constitutional question. And he sent a signal of strength to Tehran on the eve of new diplomatic negotiations.

But this victory carries an institutional cost that will be paid over time. Every time Congress abandons a constitutional prerogative — here, the oversight of presidential wars — it makes that abandonment a little more normal, a little more permanent. The next war powers resolution will be even harder to advance, because this precedent will have been set. That is how democracies weaken: not in a single great collapse, but through the accumulation of small institutional surrenders that ultimately change the nature of the system.

The defense of the West in this global context

In this context of multiple tensions — the Iran-USA war, the war in Ukraine, China's rise in power, the military-technological complex in full expansion with $12.3 billion in venture capital invested in defense in the first half of 2026 — the West must find coherence between its growing military power and its fundamental democratic values. Those values include civilian and parliamentary oversight of the armed forces, transparency in war decisions, and the institutional accountability of leaders who commit their nations to conflict.

Zelensky's Ukraine, which has been fighting since 2022 for its survival and for European democratic values, deserves a West that remains faithful to those values not only in words but also in institutional practice. A West that abandons parliamentary oversight of wars to gain operational flexibility no longer fully embodies the model it claims to defend. That is the profound challenge this late-night Senate vote poses to American democracy.

Signed Maxime Marquette, columnist

Columnist's transparency box

Editorial positioning

This investigation is based exclusively on facts reported by identified and dated sources. Editorial passages in italics represent the columnist's personal opinions and are clearly marked. The columnist has no ties to military-industrial lobbying groups or to American or Iranian political parties.

Limits of the analysis

The information available on the late-night Senate vote of June 25, 2026, the Vance-Iran talks in Geneva, and defense investment data come from sources dated June 21 to 25, 2026. Diplomatic developments after that date are not covered. The precise substance of the Capitol lunch between Trump and dissident Republican senators was not fully disclosed in available sources.

Sources

Primary sources

The Guardian — Senate rejects Iran war powers resolution, Trump news — June 25, 2026

Chosun Biz — Defense VC $12.3B H1 2026, Iran war 106 days, Anduril $20B contract — June 22, 2026

Secondary sources

ArentFox Schiff — US legal and commercial context June 2026 — June 25, 2026

Politico — Supreme Court and political decisions of June 25, 2026 — June 25, 2026

Aletihad — New US-Iran negotiations in Geneva planned — June 21, 2026

NPR — Vance and Iranian officials hold high-stakes talks in Switzerland — June 22, 2026