The war against Iran, launched by the United States and Israel six months ago, was conceived as a lightning campaign against a weakened and already battered enemy.
As far as is currently known, the immediate trigger was the unrest that swept Iran in January, which appears to have convinced the Israeli and American leadership that the government in Tehran was teetering on the brink of collapse and required only a final push.
At the beginning of the campaign, Donald Trump confidently predicted that the war would last a month or six weeks, and sometimes suggested it could be over even sooner. Instead, it’s become one of the defining events of the 21st century and its long-term consequences may ultimately prove comparable to those of the September 11 attacks or Russia’s military operation in Ukraine, and perhaps even surpass them.
Among the most important consequences is the damage inflicted on the United States’ position as the principal guarantor of security for the Arab states of the Persian Gulf, a role Washington gradually assumed after the Second World War, initially alongside Britain and later largely on its own.
The war has exposed two fundamental weaknesses in that first, the United States has proved unable to protect the oil infrastructure and essential services of the Gulf monarchies from devastating attacks by a middle-ranking power such as Iran, and second, it has failed to guarantee freedom of commercial navigation in strategically important waters against attacks by Iran and its Houthi allies in Yemen.
This is important far beyond the military sphere where America’s role as the Gulf’s security guarantor, spectacularly demonstrated during Operation Desert Storm in 1990-91, became one of the foundations of the post-Cold War international order. It influenced not only the foreign policies of the Arab monarchies but their financial decisions, as they invested enormous sums in the United States partly because their relationship with Washington provided them with security.
The scale of the American commitment in 1990 illustrates how much has changed.
To defend Saudi Arabia and defeat Iraq, the United States concentrated about 540,000 troops in the region, roughly a quarter of the active-duty strength of the US armed forces at the time. Seven of the Army’s 18 active divisions and two of the Marine Corps’ three divisions participated, while six of America’s 15 aircraft carriers were deployed, along with approximately 1,600 of its 6,500 combat aircraft.
Desert Storm was ultimately an overwhelming American victory achieved at remarkably low human cost, but American planners didn’t know beforehand that casualties would be so limited. Pre-war estimates envisaged as many as 20,000 casualties, including 6,000 to 7,000 dead, but despite those projections and substantial opposition in Congress, President George H.W. Bush and his administration went ahead.
The contrast with today is amazing as the United States is no longer capable of assembling anything resembling its 1990 force in the Middle East. Around 50,000 American personnel have been deployed for the current operation against Iran, supported by approximately 300 aircraft and just over 20 warships, including two aircraft carriers.
Nor has Washington managed to mobilize its allies on anything approaching the same scale, while Britain alone contributed about 35,000 personnel to the campaign against Iraq in 1990, no American ally from outside the Middle East has made a comparable contribution to the present war.
There has therefore been a radical decline in the resources the leading Western power can mobilize to defend what it regards as vital global interests, as well as in its ability to draw upon allied military power.
Curiously, this has happened without a comparable decline in America’s share of global military expenditure, given the United States accounted for roughly 35-37% of world military spending in 1990 and around 33% in 2025. This discrepancy should encourage greater skepticism about attempts to measure military power simply by comparing defense budgets.
Yet resources are only part of the explanation as more important is Washington’s apparent inability to use effectively the formidable capabilities it still possesses.
The United States undoubtedly retains the technical capacity to inflict a crushing military defeat on Iran and overthrow its government through a sufficiently large joint military operation, even with substantially fewer forces than it deployed against Iraq in 1990, but the obstacle is the price.
Any decisive operation involving a substantial ground component would probably produce many thousands of American casualties, including hundreds, and more likely thousands, of deaths. The political system that accepted such risks in 1990 appears unwilling to accept them today.
The extraordinary effort mounted on April 5, 2026, to rescue the pilot of an F-15 shot down by Iran illustrates the problem, as the United States reportedly committed 176 aircraft to the rescue and lost three manned aircraft and two or three helicopters, representing some $300 million worth of equipment.
The determination to save individual servicemen is understandable, but a military cannot expend resources on that scale to prevent individual casualties while simultaneously fighting a major war intended to achieve decisive strategic objectives.
The same caution is visible elsewhere, seeing as American troops have been kept away from the most dangerous areas, while US warships have operated at considerable distances from the Iranian coast, reducing their effectiveness. Washington has also sought to minimize public attention to its casualties, despite their relatively small number, in marked contrast with its approach during the much more dangerous operations of the early 1990s.
Then there is the financial constraint. The 1990-91 Gulf campaign cost the US budget about $64 billion, or around $120 billion when indirect costs are included. Adjusted for inflation, that would exceed $300 billion today. By mid-July, the current operation against Iran had already cost approximately $37 billion. The total is now likely between $40 billion and $50 billion, even though the campaign has failed to produce the decisive result originally envisaged.
The lesson is therefore more complicated than the simple claim that American military power has disappeared because the United States retains enormous military and financial resources. What’s changed is its ability to concentrate those resources, mobilize allies, and accept the human and financial costs required to achieve decisive political objectives.
Desert Storm demonstrated what American military supremacy looked like at its height, but the war against Iran is revealing something very different, a superpower that can still inflict enormous damage, but increasingly struggles to convert its military superiority into the political outcomes it seeks.
