Supporters of the United States and Israeli military campaign against Iran argue that weakening Tehran by degrading its missile capabilities, crippling its navy and reducing its ability to project power through regional allies will make the Middle East safer. But this strategy rests on an assumption that a weaker Iran would produce a more stable region. In reality, destabilising one of the Middle East’s largest and most strategically important states could unleash forces far more dangerous than the status quo.

According to briefings provided to congressional staff in Washington, DC, there was no intelligence suggesting Iran was planning to attack the US. Yet military escalation continues in the belief that weakening Iran will ultimately serve US interests. If that assumption proves wrong, the consequences could be severe not only for the region but also for American strategic interests.

The first danger is internal fragmentation. Iran’s population is ethnically diverse. While Persians form the majority, the country is also home to large Azeri, Kurdish, Arab and Baloch communities, among others. Several of these groups already have histories of political tension or insurgency, including Kurdish militant activity in the northwest and a long-running Baloch insurgency in the southeast.

A strong central state has largely kept these fault lines contained. But if Iran’s governing structures weaken significantly, those tensions could intensify. The result could resemble the fragmentation seen in other Middle Eastern states after external military pressure or regime collapse.

Recent history offers sobering examples. In Iraq, the dismantling of state institutions after the 2003 US invasion created the conditions for years of sectarian violence and ultimately the rise of ISIL (ISIS). Libya’s state collapse in 2011 left the country divided between rival governments and armed militias, a crisis that persists more than a decade later. Syria’s civil war produced one of the worst humanitarian catastrophes of the century while turning large swaths of territory into battlegrounds for militias and extremist groups. At the height of the conflict, ISIS was able to seize and govern territory across eastern Syria, declaring a so-called caliphate that controlled millions of people.

Iran’s collapse would produce an even more dangerous scenario. Its population is far larger than Iraq, Libya or Syria, and its territory borders multiple conflict-prone regions. The emergence of armed factions, ethnic militias or insurgent groups inside Iran could quickly transform the country into another arena of prolonged instability.

Such instability would not remain local. Iran sits at the heart of the Gulf, one of the world’s most strategically important energy corridors. Roughly a fifth of global oil supplies pass through the Strait of Hormuz along Iran’s southern coastline. Armed factions, rival militias or uncontrolled naval forces operating along Iran’s coast could disrupt shipping lanes, attack tankers or try to block access to the strait, turning a regional crisis into a global energy shock. That would have consequences far beyond the Middle East. Higher energy prices would ripple through global economies, affecting everything from transportation costs to inflation. American policymakers often view energy instability as a regional problem, but in reality, it quickly becomes a global one.

The strategic consequences would extend further. Iran currently serves as a central node in a network of regional alliances and proxy groups that includes Hezbollah in Lebanon, various militia groups in Iraq and the Houthis in Yemen. These actors operate within a framework influenced, to varying degrees, by Tehran. If the Iranian state weakens dramatically, that structure could fragment. Some groups might operate independently, others might compete for influence, and still others could radicalise further without central coordination. The result would be a far more unpredictable security environment across the Middle East, which would make diplomatic engagement more difficult and military conflicts harder to contain.

Another risk lies in leadership uncertainty. Some policymakers assume that weakening the current Iranian leadership will produce a more moderate political order. But regime change rarely follows a predictable script.

Iran’s political system contains multiple competing factions, including conservative clerical networks, reformist politicians and powerful elements within the security establishment such as the Islamic Revolutionary Guard Corps (IRGC). Iran’s leadership transition is less about a single successor than about the balance of power between clerical institutions, elected offices and the security apparatus. If the existing leadership were weakened or removed during wartime conditions, that balance could quickly unravel. The IRGC, which already commands vast military and economic resources, could try to consolidate authority, potentially pushing Iran towards a more overtly militarised political order. In such an environment, more radical actors, particularly those who view compromise with the US as impossible, could gain influence.

There is also little evidence that sustained military strikes will generate pro-American sentiment among the Iranian population. History suggests that external pressure often strengthens nationalist sentiment rather than weakening it. The 2003 invasion of Iraq, for example, did not produce pro-American attitudes but instead fuelled resentment and insurgency. Similarly, repeated Israeli military campaigns in Lebanon have tended to strengthen support for Hezbollah rather than weaken it.

Beyond the Middle East itself, instability in Iran could also trigger significant migration flows. Iran already hosts millions of refugees from neighbouring countries, particularly Afghanistan. If internal conflict were to erupt inside Iran, even a small share of Iran’s population of more than 90 million people seeking refuge abroad could produce migration flows far larger than those seen during recent Middle Eastern crises.

Many of those migrants would likely move towards Turkiye and eventually Europe, placing additional pressure on governments already grappling with migration crises. While this may appear distant from American shores, the political consequences for US allies in Europe would inevitably affect transatlantic relations and Western cohesion.

Taken together, these risks illustrate a broader strategic problem. Weakening Iran may appear attractive to the US from a narrow military perspective, but destabilising a large regional power rarely produces orderly outcomes.

The United States has confronted similar dynamics before. The collapse of state authority in Iraq after 2003 did not eliminate threats in the region; it produced new ones. Libya’s fragmentation after 2011 created an enduring security vacuum. Syria’s civil war turned into a multisided conflict that reshaped the politics of the entire region.

For Washington, the question should be whether the long-term consequences of destabilising Iran would ultimately make the region and the world more dangerous. If recent history offers any guidance, destabilising Iran may ultimately create the very threats Washington hopes to eliminate.

The views expressed in this article are the author’s own and do not necessarily reflect Al Jazeera’s editorial stance.