In conventional warfare since the Industrial Revolution, numbers and weaponry have often been decisive. Victory was generally understood to mean defeating an opposing army and breaking the structures that enabled its state and society to endure.
Recent decades have complicated that understanding of power and victory. The 2026 war involving Iran, with no end yet in sight, has brought the ability to disrupt supply chains to the fore. Attacks on sources of energy, minerals, water and food, as well as on resources needed for biotechnology, can threaten a society’s capacity to function. Environmental destruction can extend a conflict’s effects beyond the fighting itself.
There is an irony here. Advocates of globalisation argued that trade and technology would make war prohibitively costly. Economic ties would bind rivals together and reduce their incentive to use force. The networks they envisaged did emerge, making secure supplies of oil, food and medicine increasingly important. Today, those networks also carry resources on which advanced technology and AI depend. But interdependence has given states new ways to exert pressure on one another.
How globalisation created new instruments of war
In a 2019 research paper, Henry Farrell and Abraham Newman challenged the assumption that the rising cost of war would make states consistently peaceful. Global economic networks are not evenly distributed, they argued. They depend on a limited number of financial, informational and logistical hubs. States that control those hubs can weaponise “interdependence itself” by gathering sensitive information or denying an adversary access to a network.
Their argument helps explain the growing use of financial sanctions, chip export controls, restrictions on critical minerals and maritime blockades. Such measures can undermine an adversary’s ability to sustain a conflict as well as its ability to fight one. In an article published in Foreign Affairs in August 2025, Farrell and Newman described a “weaponized world economy” in which control points within interconnected networks had become tools of economic pressure.
This article examines that shift through the history of the Strait of Hormuz, the security of other maritime routes, the geopolitics of semiconductors and critical minerals, and environmental destruction in war. Together, these cases show how dependence on a limited number of routes and resources can leave even powers such as the US and China vulnerable to pressure from regional adversaries.
From Covid to Ukraine to Iran: repeated warnings
During the Covid-19 pandemic, governments confronted the security implications of disrupted supply chains. The crisis exposed the dependence of the US and European countries on China and India for essential pharmaceutical ingredients and personal protective equipment. RAND warned that serious supply chain vulnerabilities posed a national security threat requiring closer study. An Atlantic Council survey found that about 45 per cent of business experts had not considered the possibility of supply chain disruption before the pandemic.
Russia’s invasion of Ukraine in early 2022 brought another warning. European countries’ reliance on Russian energy exports gave Moscow a means of applying pressure in its confrontation with them.
The Strait of Hormuz has since drawn attention to a vulnerability with potentially global consequences: the dependence of energy shipments on passage through a narrow waterway. As President Harry Truman said: “There is nothing new in the world except the history you do not know.” The struggle over Hormuz has a history that helps explain its role in the 2026 war.
Centcom and Silkworm: the struggle over Hormuz
Washington once supported Iran’s position during the Paris peace negotiations after the First World War. After the Second World War, it opposed Soviet ambitions in Iran, which it saw as a buffer between US and Soviet influence in the Middle East. The importance oil would acquire was not yet apparent at the first of those junctures; at the second, the US had not fully inherited the Western powers’ areas of influence. Washington nonetheless maintained a friendly government in Tehran until the relationship broke down in 1979.
That year, Iran became an Islamic republic and the Soviet Union invaded Afghanistan. The Iranian revolution produced an ideological adversary for Washington, while the Soviet invasion was seen in the US as an advance towards the Gulf.
During the US embassy hostage crisis in Iran, the American military considered ways to put pressure on Tehran. David Crist describes two proposals in The Twilight War: The Secret History of America’s Thirty-Year Conflict With Iran: a naval blockade and the seizure of Iran’s Kharg Island by naval forces backed by carrier-based aircraft. About 95 per cent of Iranian oil flowed through the island to waiting tankers.
Kharg Island was lightly guarded and relatively accessible, but seizing it carried considerable risks. Japan, which imported 10 per cent of the oil it consumed from Iran, could be badly affected. A shortage on the global market might raise oil prices by 15 to 30 per cent, and Iran might kill the hostages in response. Carter examined the proposal but chose instead to attempt their rescue through Operation Eagle Claw, which failed.
Carter also set out a broader US position. Responding to the Soviet invasion of Afghanistan and the upheaval in Iran, he declared in his 1980 State of the Union address what became known as the Carter Doctrine. Any attempt by an outside force to control the Persian Gulf, he said, would be treated as an assault on US interests and repelled by military force if necessary. The region supplied more than two-thirds of the world’s exportable oil.
Crist argues that the doctrine became the basis for a military structure: the Rapid Deployment Joint Task Force, which developed into Centcom, the command responsible for the Gulf, Central Asia and East Africa. The Iran-Iraq War then tested the US commitment to protecting Gulf shipping.
During the so-called “Tanker War” of 1984–88, commercial vessels travelling to and from Kuwait came under repeated attack. The US launched Operation Earnest Will to protect them, putting the Carter Doctrine into practice at sea. Centcom subsequently took responsibility for securing tanker movements through Hormuz during regional crises.
Protecting tankers did not remove the vulnerability created by the strait itself. That became clear during the eight-year Iran-Iraq War, one of the deadliest conflicts of the 20th century outside the two world wars. Despite attacks involving Iraqi Exocet missiles and Super Étendard aircraft, Iran’s oil facilities on Kharg Island survived without a decisive strike.
The US, the Soviet Union, the Gulf states, Egypt, Yemen and Jordan supported Iraq, even as Iran occupied Iraqi territory. Historians Marion Farouk Sluglett and Peter Sluglett argue in From Revolution to Dictatorship: Iraq Since 1958 that Iraq’s supporters took Ayatollah Khomeini’s threat seriously: if Iranian oil exports were targeted, no oil would pass through Hormuz. They therefore pressed Iraq not to attack Kharg Island.
That threat shaped the limits within which the opposing sides operated. The war of 2026 challenged those limits.
Iran was also acquiring a means of threatening shipping directly. Crist recounts that, after Kuwait sought US protection for tankers, then-Iranian President Ali Khamenei called the request an insult to the region. He warned that Kuwait City and its oil facilities were within range of Iranian forces and said Iran had not yet used all its means of applying pressure.
In August 1986, Commodore Khnoush Hakimi travelled to China to arrange a secret purchase of Silkworm anti-ship cruise missiles. China agreed to sell 12 launchers and up to 100 missiles. US intelligence learned of the deal, and US Defence Secretary Weinberger raised it with his Chinese counterpart at the Pentagon. The Chinese denied it, but Weinberger told him: “We have obtained satellite and photographic images of the first shipment leaving China and being unloaded in Bandar Abbas.”
By January 1987, Iran had one operational Silkworm battery. It fired a missile towards a Kuwaiti port ahead of an Organization of Islamic Cooperation meeting, then began building a chain of 10 concrete launch platforms around the Strait of Hormuz. The CIA regarded the missiles as a major new threat to Gulf shipping and US vessels. With a range of 50 nautical miles, a Silkworm could threaten even a 400,000-tonne supertanker. Iran had gained a greater ability to disrupt oil exports and attack vessels entering or leaving the strait.
Missiles and mines gave Tehran a means of threatening passage through a critical supply route. Iran later passed that expertise to armed groups it backed.
Could freedom of navigation come under greater pressure?
Iran is not the only country whose position near a major waterway carries economic significance. In April 2026, Indonesia’s finance minister floated the possibility of charging ships to pass through the Strait of Malacca: “If we divide transit fee revenues among Indonesia, Malaysia and Singapore, that could increase revenues.” Nearly a quarter of global maritime trade passes through the strait, as do more than 80 per cent of China’s oil imports.
China has long recognised that dependence as a vulnerability. President Hu Jintao gave it a name in 2003: the “Malacca dilemma”. Chinese strategists have since sought to reduce the risk of a hostile power controlling access to the strait.
China has developed ports in Djibouti, Sri Lanka, Pakistan and Myanmar as part of the “string of pearls” strategy to diversify its maritime connections. Those investments offer limited protection, however, against a conflict that closes Hormuz or threatens Malacca.
Indonesia’s foreign minister subsequently distanced the government from the suggestion, saying Indonesia “respects freedom of navigation and of course will not impose transit fees on ships passing through the Strait of Malacca.” A Reuters report nevertheless points to concern that the precedent set at Hormuz could influence how other governments think about waterways near them.
Armed groups can also disrupt maritime routes. About 15 per cent of global maritime trade passes through the Suez Canal, whose route to the Indian Ocean runs through the Bab el-Mandeb Strait. Chinese exports worth around $160bn pass through the strait each year, including 60 per cent of those bound for Europe.
Since the outbreak of the genocidal war on Gaza in October 2023, the Houthi Ansar Allah movement has used its position near Bab el-Mandeb, through which 9m barrels of oil passed daily, to threaten shipping. It has targeted more than 100 commercial vessels. Major shipping companies have rerouted ships around the Cape of Good Hope, adding more than $1m and 10 to 14 days to a voyage.
The effects extend beyond China and Europe. The disruption contributed to a 90 per cent fall in container ship traffic through the Suez Canal in 2024. Canal revenues reached their lowest level in two decades, while shipping prices on the Rotterdam–Shanghai route rose by 80 per cent between 2023 and 2025.
In a Baker Institute paper, researcher Jim Krane described the Houthi attacks as imposing “economic sanctions” on the backers of “Israel.” He argued that their effects reached EU countries, Britain and the Gulf Arab states and affected those countries’ relationships with “Israel.” Unlike formal state sanctions, such pressure requires no decision by the United Nations. Its effects on state behaviour may, in some circumstances, be greater. Researcher Scott Romaniuk makes the broader point, saying: “Non-state actors today can influence trade and regional politics far beyond their geographic boundaries because of repeated campaigns that exploit the controllability of sensitive major maritime choke points from Hormuz to Malacca.”
The importance of these routes is itself a consequence of globalisation. In an article titled “China and Maritime Chokepoints: Hormuz, Malacca, and Indo-Pacific Vulnerability”, researchers writing in The Diplomat argue: “Globalization still depends fundamentally on maritime security, and as great-power competition intensifies, contestation over vital waterways is likely to remain a prominent strategic feature in the Indo-Pacific, stretching from the Suez Canal and the Red Sea to the Strait of Malacca and beyond. Rather than being neutral conduits of globalization, these corridors have become structural sites of geopolitical competition, shaping rather than facilitating the distribution of global power.”
Taiwan’s silicon shield — and its vulnerabilities
The ability to make advanced semiconductors has become an important source of economic and strategic power. Taiwan sits at the centre of that industry and of fears about a future conflict with China.
Through TSMC, Taiwan produces more than 90 per cent of the world’s most advanced chips — those below seven nanometres — used in products ranging from smartphones to AI systems and advanced weapons. That position has given rise to the idea of a “silicon shield”: the economic damage a war would cause to countries dependent on Taiwanese chips might deter an attack on the island.
China would also bear costs. Researcher Viktor Simov argues that an attack could disrupt its electronics and military industries. China imported 61 per cent of its semiconductors from Taiwan in 2020. As it pursued domestic production, that share fell to 54 per cent in 2023, potentially weakening Taiwan’s economic deterrent.
China still faces obstacles to self-sufficiency. Despite investing nearly $150bn, its manufacturing remains behind Taiwan’s, while successive US administrations have imposed further obstacles. Domestic production on a sufficient scale therefore appears unlikely in the near term.
Even if China reduced its dependence on Taiwanese chips, it would still have to weigh the US response to any attack. Semiconductors are central to US defence systems and to the civilian economy. A decline in American microelectronics capabilities could weaken the country’s ability to defend itself and its allies.
The link between chips and national security has shaped US policy for decades. In the mid-1980s, President Ronald Reagan stressed the need to maintain US leadership in semiconductors. Satellites, stealth aircraft and cruise missiles powered by advanced electronics offered a way to counter the Soviet military’s numerical superiority.
The US remains reliant on Taiwan for chips it cannot produce domestically at the scale and level of technology it needs. The two have consequently deepened a trade relationship that also matters to the AI competition between the US and China.
That relationship creates uncertainty for Taiwan. Donald Trump’s efforts to bring 40 per cent of chip and semiconductor manufacturing to the US have raised questions there about Washington’s long-term intentions. Yet Taipei continues to work closely with it. At the beginning of 2026, Washington and Taipei launched the “Pax Silica”” project, under which Taiwan pledged to invest $250bn in semiconductors and AI in the US. The partnership ties Washington’s technological ambitions more closely to Taiwan’s industry, although an investment pledge alone cannot establish how the US would respond to a future threat to the island.
The industry has other dependencies. Taiwanese semiconductor manufacturers need gallium and germanium, metals supplied almost exclusively by Chinese companies. China has used restrictions on these materials as leverage in its trade and technology dispute with the US: Chinese germanium exports to Taiwan stopped entirely between 2022 and 2024.
The 2026 war involving Iran exposed another vulnerability. Qatar, which produces 34 per cent of the world’s helium, was forced to halt production, sharply reducing supplies. Semiconductor plants need helium to maintain the inert conditions used in clean rooms.
The silicon shield, then, has limits. Taiwan’s technological lead gives other countries an interest in its security, but the industry relies on materials from China and on supply chains exposed to conflict elsewhere, including the Middle East. Its reliance on US protection may also be a vulnerability when successive administrations pursue “America First” policies. So far, however, Taiwan’s semiconductor position remains part of the calculation facing China, whose armed forces are much larger and more advanced than Taiwan’s.
China’s power over critical minerals
Hydrogen is seen as a way to diversify energy sources beyond electricity and liquefied gas. But its production depends on critical minerals concentrated in a limited number of places, giving countries that control their supply potential bargaining power.
Lithium, cobalt, nickel and rare earths are also essential to batteries, semiconductors and the permanent magnets used in precision missiles, fighter jets and radar systems. They matter to the transition to electric vehicles and renewable energy as well as to military production.
China does not hold the largest reserves of all these minerals, but it dominates their processing. It controls about 90 per cent of global rare earth processing, nearly 80 per cent of refined cobalt production and more than 70 per cent of lithium refining. As one report argues, the electric car’s supply chain has become a source of political power for China.
Beijing has begun to use that position as leverage. In October 2025, its Commerce Ministry announced new export controls on heavy rare earths and permanent magnets that specifically targeted military users outside China for the first time.
Gracelin Baskaran argues at the Center for Strategic and International Studies that the restrictions threaten supply chains for US defence technology. Rare earths are important to F-35 aircraft, Virginia- and Columbia-class submarines, Tomahawk missiles, radar systems, Predator drones and families of smart bombs. The US is already struggling to keep pace with production needs, she writes, while China is expanding munitions manufacturing and acquiring advanced platforms and equipment at an estimated five to six times the US rate.
The constraints extend beyond defence. Processing capacity outside China currently meets no more than 20 per cent of global demand for these minerals. Restrictions on supply can therefore affect electric vehicles and semiconductor components as well as weapons, posing a risk to Washington’s military advantage.
NATO has recognised rare earths as a defence supply concern. At its Summit Defense Industry Forum, 12 allied countries launched a project to coordinate the purchase and management of critical resources for military industries. The move followed a reported 500 per cent rise in the cost of rare earth magnets used in precision-guided munitions and radar systems.
The Democratic Republic of Congo, meanwhile, accounts for about 70 to 75 per cent of global raw cobalt production. Under China’s Belt and Road Initiative and Going Out strategy, Chinese companies finance about 15 of the country’s 17 cobalt mines. China also holds a dominant share of the chemical refining that turns raw cobalt into materials suitable for batteries.
The International Renewable Energy Agency argues that the move towards cleaner energy changes the meaning of energy security. It does not end geopolitical competition; it shifts competition towards the resources and processing capacity needed for new technologies.
Environmental destruction as a weapon
Environmental damage in war is not new. Between 1962 and 1971, US and South Vietnamese forces carried out Operation Ranch Hand, spraying about 80m litres of herbicides, most notably Agent Orange, over land in Vietnam. The aim was to strip Viet Cong forces of vegetation cover and destroy crops. The chemicals affected about 2.9m hectares of farmland and forest and exposed millions of civilians to toxic substances, including dioxin, whose effects persist.
A group of US scientists subsequently coined the term “ecocide” to describe large-scale environmental destruction. In 1976, the United Nations adopted a treaty prohibiting the military or other hostile use of environmental modification techniques. Environmental damage in more recent wars has renewed questions about the limits of such protections.
A 2024 UN Environment Programme report documented extensive damage in Gaza:
- Water, sanitation and hygiene systems had ceased functioning, and all five wastewater treatment plants had shut down. Sewage contaminated beaches, coastal waters, soil and freshwater with pathogens, nutrients, microplastics and hazardous chemicals, posing immediate and long-term risks to residents’ health, marine life and farmland.
- Five of Gaza’s six solid waste facilities had been damaged. By November 2023, 1,200 tonnes of rubbish a day were accumulating around camps and shelters. A shortage of cooking gas forced families to burn wood, plastic and waste, exposing women and children in particular to danger. Those fires, together with fuel combustion, were likely to have sharply worsened air quality.
- Munitions containing heavy metals and explosive chemicals used in densely populated areas contaminated soil and water, creating health risks that would persist after the fighting. Unexploded ordnance posed a particular danger to children.
- Destroyed solar panels were also expected to release lead and other heavy metals into soil and water.
By January 2025, some 80 per cent of Gaza’s tree cover had been destroyed and about half its agricultural land had become barren. Seawater had entered the groundwater, leaving 97 per cent of water that had once been drinkable no longer fit to drink.
War can cause environmental damage without the environment itself being the intended target. Along Gaza’s eastern border, however, a report published in October 2023 with Palestinian and Israeli human rights organisations documented Israeli aerial spraying of herbicides since 2014. Winds carried the chemicals up to 1,200 metres into Gaza, damaging farmers’ crops and, according to the report, forcing many to leave their land. Israel’s Defence Ministry acknowledged about 30 spraying operations.
Another report argued that the spraying and related practices caused economic and demographic changes near the fence by impoverishing farming communities and undermining their ability to remain on their land. Israeli forces also sprayed the herbicide “glyphosate” in southern Lebanon after the invasion at the start of 2026, reportedly at concentrations 20 to 30 times higher than normal rates.
Reports and journalistic investigations have also described damage in southern Lebanon and, later, areas of southern Syria near the Golan. They cite the use of weapons with lasting environmental effects, including white phosphorus, as well as aerial herbicide spraying. The Lebanese government and rights and environmental organisations say the consequences extend beyond immediate military damage to farmland, forests, water sources and biodiversity. They warn of risks to food security and obstacles to residents’ return.
Israeli operations have burned large areas of agricultural land, including centuries-old trees, affecting biodiversity and the soil’s resistance to erosion and desertification. Scientific reports indicate that white phosphorus residues and heavy metals from munitions can remain in soil for long periods, reducing fertility and agricultural productivity and raising the cost of restoring the land.
Russia faces accusations of environmental destruction in Ukraine. They include the deliberate destruction of the Kakhovka Dam, which had supplied about 700,000 people. Its destruction caused extensive flooding and contaminated water sources; without the water it provided, 600,000 hectares of farmland face a risk of desertification. Mines have also left large areas of Ukraine dangerous to use. According to Killing the Future: The Reverberating Effects of Russia’s Ecocide in Ukraine, mercury, arsenic and mines have contaminated 500,000 hectares of agricultural land. The damage threatens a country that has supplied food to Europe and to Mozambique, Djibouti and Syria. The report estimated in February 2025 that removing the mines would cost about $37.5bn.
Environmental harm can also arise during a government’s war against its own people. A report published in December 2025 described how fuel shortages and economic desperation in north-eastern Syria drove illegal logging. Organised traders, charcoal producers, armed groups and businessmen linked to elites benefited from forest fires. Some fires were deliberately set, the report said, by commercial elites tied to the Assad regime to clear land for construction, industrial use or profitable charcoal production. The fires destroyed livelihoods and permanently changed fragile ecosystems.
Gaps in the legal definition and criminalisation of ecocide leave uncertainty about how such destruction can be prosecuted. That uncertainty may make it easier for powerful states to inflict long-term environmental harm in war, including damage that disrupts communities and persists after the fighting.
The hydra
States increasingly have to think about deterrence beyond nuclear weapons and conventional military strength. Control of economic resources and supply routes can give a country means of applying pressure even when it cannot match an adversary’s armed forces.
In Greek mythology, cutting off one of the hydra’s heads causes two to grow in its place. The image captures a feature of contemporary conflict: pressure on one route or resource can expose dependence on another. Control of supply chains, maritime passages, critical minerals and the environment can inflict lasting harm; the ability to endure that pressure has become a source of power too.
Conventional military force remains central to war. But it can be used alongside other measures: closing a shipping route, withholding a chip, restricting mineral exports or contaminating soil and water.
The Carter Doctrine and the struggle over Hormuz, Taiwan’s silicon shield and China’s Malacca dilemma, the use of herbicides in Vietnam, Gaza and southern Lebanon, and competition over Congolese cobalt and Chinese rare earth magnets all point to the same vulnerability. In an interconnected world, power depends partly on who controls the routes and resources others need — and on whether those facing that pressure can withstand it.