akistan has compelling reasons to be deeply concerned about the prospect of a US attack on Iran that results in the dismantling or severe weakening of the Iranian state. History offers a sobering reminder that conflicts in neighboring countries rarely remain confined to national borders. When the Soviet Union invaded Afghanistan in 1979, Pakistan was drawn into the geopolitical struggle as a frontline state, a role that imposed costs far exceeding any short-term strategic gains. What followed was not a temporary security challenge but a decades-long ordeal.

Millions of Afghan refugees crossed into Pakistan and settled for generations, altering the demographic balance and placing immense strain on social services. Militant networks flourished under the cover of war and foreign patronage, gradually embedding themselves into Pakistan’s internal security landscape. Sectarianism intensified, ethnic fault lines hardened and the country’s security architecture suffered serious damage. Its consequences continue to shape Pakistan’s politics and stability. This experience underscores a fundamental geopolitical reality: instability next door does not remain external. In much the same way, a US-led assault on Iran will not be a clean or contained military operation. Iran’s size, population, strategic depth and regional influence mean that any attempt to dismantle its regime will generate prolonged instability, retaliation and adaptive responses that will reverberate across the region.

Pakistan’s exposure to such fallout is magnified by geography. It shares a long and porous border of nearly nine hundred kilometers with Iran, running through the ethnically sensitive and economically marginalised Baloch region. This area has long been marked by separatist insurgencies, weak governance and cross-border militant activity. Armed groups such as BLA, Jundullah, Majeed Brigade and Jaish al-Adl already operate along this frontier, exploiting gaps in state control on both sides. Even in periods of relative calm, tensions have periodically escalated into major confrontations.

The Iranian missile and drone strikes inside Pakistan’s Balochistan in January 2024, which Islamabad condemned as a violation of its sovereignty, demonstrated how quickly localised tensions can spill across borders during moments of heightened stress. If Iran were to experience regime collapse or prolonged internal conflict following an external attack, border management will deteriorate sharply. Lawlessness, smuggling and militant movement will increase, transforming an already fragile frontier into a major and persistent security liability for Pakistan.

One of the gravest dangers in such a scenario will be the strengthening of divisive and insurgent forces that already command considerable influence in Pakistan’s western provinces. A weakened or fractured Iranian state will struggle to police its peripheral regions, allowing militant and separatist groups greater freedom of movement, coordination and recruitment. Pakistan already fears that instability in Iran could enable armed networks to consolidate across borders, linking insurgents on both sides of Balochistan into a more cohesive and emboldened movement. Such a development will not only intensify the insurgency in Balochistan but could also energise dormant or fragmented separatist narratives. In Khyber Pakhtunkhwa, where militancy has been sustained by decades of regional turmoil, the perception of a collapsing regional order could further radicalise armed actors and deepen antagonism toward the center. The empowerment of these divisive forces will stretch Pakistan’s security apparatus, widen political fractures and erode the already fragile trust between the state and peripheral regions.

Humanitarian pressures will add another destabilising layer. War and regime collapse almost inevitably produce large-scale displacement. Pakistan, already hosting millions of refugees from Afghanistan, could face refugee inflows from Iran. Given Pakistan’s strained economy, limited fiscal space and overburdened public services, absorbing another wave of displaced populations will place enormous pressure on social cohesion and governance capacity. These humanitarian challenges will be compounded by economic disruption.

Iran occupies a central position in regional energy flows and trade routes. Any large-scale conflict will disrupt markets, raise energy prices and threaten maritime security, particularly around the Strait of Hormuz. Pakistan’s own economic ambitions, including regional connectivity and infrastructure projects such as the China-Pakistan Economic Corridor, especially those passing through Balochistan, will become increasingly vulnerable in an environment of regional instability and heightened insecurity.

The country is already grappling with serious internal fault lines. Balochistan remains trapped in a cycle of insurgency rooted in political exclusion, inequitable resource distribution and chronic underdevelopment. Khyber Pakhtunkhwa continues to bear the aftershocks of Afghan instability, militant violence and socioeconomic stress. A major conflict in neighbouring Iran will not unfold in isolation; it will interact with these vulnerabilities, intensifying grievances, emboldening armed actors and stretching state capacity at a moment when Pakistan can least afford additional strain.

The strategic concerns surrounding such a scenario are reinforced by the insights of leading international scholars. John Mearsheimer’s realist critique of military intervention emphasises that great powers consistently underestimate the costs of regime-change wars while vastly overestimating their ability to control outcomes. His work highlights how interventions designed to alter regional balances often generate unintended consequences, creating new centers of resistance and instability rather than lasting security. Applied to Iran, this logic suggests that dismantling a major regional power will unleash forces beyond the control of external actors, inevitably drawing neighbouring states like Pakistan into the resulting chaos.

Fareed Zakaria’s analysis of Middle Eastern politics further underscores the deep interconnectedness of regional dynamics. He argues that simplistic military solutions are ill-suited to societies shaped by complex histories, rivalries and power struggles. An attack on Iran will not merely weaken or remove a regime; it will fundamentally alter how states across the region calculate their security, alliances and domestic politics. For Pakistan, this will mean navigating an even more volatile strategic environment while simultaneously managing deep internal stresses.

Jeffrey Sachs has repeatedly warned that wars involving major powers and strategically significant states carry global risks. His caution that a conflict with Iran could escalate beyond regional boundaries reinforces the idea that such wars rarely remain localised. When great powers clash over critical regions, the effects cascade outward, destabilising economies, security architectures and political systems far removed from the original battlefield.

Vali Nasr’s work on regional politics further strengthens this assessment. He emphasises that conflicts in the Middle East generate enduring ripple effects for neighbouring states, shaping trade patterns, sectarian relations and internal political dynamics. Even without a full-scale war, tensions between Iran and Israel have affected Pakistan through border insecurity, trade disruption and heightened sectarian sensitivities. A direct assault on Iran will likely magnify these pressures dramatically, reshaping the regional security environment in ways that Pakistan could not escape.

Taken together, history, geography, internal vulnerabilities and expert analysis converge on a clear conclusion. Pakistan cannot afford to view a potential US attack on Iran as a distant or isolated event. The Afghan experience demonstrates that spillover instability is not a theoretical possibility but a lived and costly reality. Shared ethnic ties, porous borders and fragile internal cohesion make Pakistan particularly exposed. Its existing economic and security challenges will be severely amplified by regional chaos. The consistent warning from scholars across ideological and disciplinary lines is that war—especially regime-change war—rarely stays contained.

Under these circumstances, Pakistan must employ every diplomatic resource at its disposal to discourage and stall such an eventuality. Strategic restraint, regional diplomacy, engagement with major powers and coordination with neighbouring states are not optional choices but urgent necessities. A US attack on Iran aimed at dismantling its regime will send shockwaves across the region. Its aftershocks will travel deep into South Asia. Pakistan will be among the most vulnerable states in its path. Such a crisis will not merely complicate Pakistan’s foreign policy; it will pose a profound threat to its national security, economic stability and social cohesion.

The writer is a professor in the Faculty of Liberal Arts at the Beaconhouse National University, Lahore.