Iran-US-Israel War 2026: Global Impact & Trump’s ‘Diffuse Unilateralism’

The death of Ayatollah Ali Khamenei, Iran’s Supreme Leader, in a February 28, 2026 airstrike, marked a brutal apex in a three-year conflict with Israel and the United States. The escalation, beginning with unprecedented missile attacks in April 2024, culminated in a coordinated assault on Iranian infrastructure and leadership, including the targeting of a girls’ school resulting in over 170 casualties. Reports indicate the school bombing occurred amidst the broader strikes, raising immediate questions about proportionality and targeting protocols.

This conflict isn’t simply a bilateral struggle. It represents a fracturing of the post-Cold War international order, and a challenge to the principles of multilateralism. The United States, under the Trump administration, has pursued a foreign policy increasingly characterized by what analysts are calling “diffuse unilateralism” – a willingness to act independently, bypassing traditional alliances and international institutions. This approach, coupled with Israel’s assertive regional policy, has created a volatile environment in West Asia, with global repercussions extending far beyond the immediate conflict zone.

The Unraveling of Diplomacy and the Path to War

The immediate trigger for the February 28th attacks was the breakdown of diplomatic negotiations regarding Iran’s nuclear program. Despite President Trump’s assertions in 2025 that US bombing had “obliterated” Iranian nuclear facilities, negotiations continued until shortly before the final escalation. This suggests a disconnect between stated US objectives and the reality on the ground, and raises questions about the sincerity of diplomatic efforts. The history of these negotiations, stretching back years, has been marked by mistrust and shifting red lines from all parties involved.

The initial missile attacks in April 2024, and the subsequent US entry into the conflict in 2025, failed to achieve a decisive outcome. Iran, despite facing significant pressure, continued to develop its nuclear program and maintain its regional influence. The selective targeting of Iranian proxies by Israel, beginning in 2024, further destabilized the region, undermining the leadership of groups like Hamas and Hezbollah. The loss of Iranian President Ebrahim Raisi in a helicopter accident in May 2024, while not directly linked to the conflict, added to the sense of instability and uncertainty.

Regional and Global Fallout

The war’s impact extends far beyond Iran’s borders. Neighboring countries have been consistently targeted by Israeli and Iranian air strikes, resulting in thousands of casualties and widespread destruction of civilian infrastructure. From Türkiye to Oman, the region is grappling with a humanitarian crisis. The closure of the Iranian side of the Strait of Hormuz, a critical waterway for global oil supplies, placed the global economy under significant strain. This action, intended to exert pressure on the US and its allies, disrupted supply chains, drove up oil prices, and created chaos in global transportation networks.

The conflict has too had military repercussions. US military bases in Bahrain, the UAE, Qatar, and Saudi Arabia have become targets of Iranian missiles, as have NATO facilities in Cyprus and Türkiye. Six US servicemen and a French peacekeeper stationed in Iraq have been killed. Trump’s initial promise to escort tankers through the Strait of Hormuz was later retracted, replaced by a call for “friendly nations” to maintain security in the region – a request that received a lukewarm response.

A Shifting Global Alignment

The international response to the war has been fragmented. The United Nations Secretary-General Antonio Guterres has repeatedly called for a ceasefire, but to no avail. Pope Leo XIV has also issued appeals for peace. Iran’s recent accession to the BRICS+ group has not translated into concrete support, with the alliance remaining largely silent on the conflict. Russia has benefited from the surge in oil prices, resuming embargoed exports, and has offered to mediate a deal with Iran, potentially leveraging the situation to gain concessions from the West regarding the war in Ukraine. China, vulnerable to disruptions in Middle Eastern oil supplies, has emphasized the principles of territorial integrity and international law, but has refrained from taking a strong stance. India has maintained a low profile, keeping diplomatic channels open with both sides.

The European Dilemma and the Erosion of the Liberal International Order

The European Union finds itself in a particularly difficult position, torn between supporting the US-Israeli war effort, condemning the Iranian regime, and upholding the principles of a rules-based international order. The political divisions within Europe have been laid bare, with President of the EU Commission Ursula Von der Leyen acknowledging the conclude of “European custody” over the existing world order. Her statement reflects a growing recognition that the post-Cold War international system is undergoing a fundamental transformation.

The UK has reluctantly allowed the US to use its military bases, while Prime Minister Keir Starmer has emphasized that the war is at odds with international law. France has offered to mediate talks between Israel and Lebanon, and Spain has championed a “no war” stance. This divergence of views highlights the challenges facing the EU in navigating a world increasingly characterized by fragmentation and competition.

Diffuse Unilateralism and the Future of US Foreign Policy

The current conflict in Iran is a manifestation of a broader trend in US foreign policy – what some analysts term “diffuse unilateralism.” This approach, characterized by a willingness to act independently and bypass international institutions, represents a departure from the multilateralism that defined much of the post-Cold War era. It is not simply about pursuing national interests, but about reshaping the international order to better suit US priorities, even at the expense of collective security and global stability.

This strategy contrasts sharply with previous US interventions in the Middle East, such as the 1991 Gulf War or the 2003 invasion of Iraq, which were undertaken with broader international coalitions and under the auspices of the United Nations. The current approach relies on displays of military strength, the exploitation of normative loopholes, and the mobilization of smaller powers through selective deals. It prioritizes short-term gains over long-term institutional investment, and eschews the burdens of collective action.

What’s Next?

The immediate future remains highly uncertain. With Ayatollah Mojtaba Khamenei reportedly injured and unable to publicly assume leadership, a succession crisis looms in Iran. While the killing of his father may serve to rally support for the regime, it also creates an opportunity for internal dissent and external pressure. The US and Israel are likely to continue their military pressure on Iran, but a full-scale invasion remains unlikely. The focus will likely shift to containing Iran’s regional influence and preventing it from acquiring nuclear weapons.

The broader implications of the conflict are far-reaching. The erosion of the Liberal International Order, the rise of diffuse unilateralism, and the fragmentation of the global political landscape are all trends that are likely to accelerate in the coming years. The war in Iran serves as a stark reminder of the fragility of peace and the dangers of unchecked power. The path forward will require a renewed commitment to diplomacy, multilateralism, and a shared understanding of the interconnectedness of global challenges.