As Pakistan’s Inter-Services Intelligence (ISI) marks its 77th year, what should have been an occasion to reflect on national service is instead a grim reminder of a legacy steeped in covert warfare, cross-border terrorism, and regional destabilisation.

Established in 1948, the ISI has grown far beyond its original mandate of military intelligence. Today, it is widely regarded as the architect of proxy conflicts and terror networks that have wreaked havoc across South Asia, particularly in India and Afghanistan, while also suffocating Pakistan’s own democratic and civil fabric.

This analysis traces the ISI’s deadly legacy, examining its support to militant outfits, interference in neighbouring states, and the radicalisation of its leadership that continues to pose a grave threat to regional and global peace.

From Intelligence Arm to Shadow Government

Originally created to serve as an internal coordinating agency for Pakistan’s armed forces, the ISI quickly transformed into a parallel power centre. By the late 1970s and early 1980s, under the dictatorship of General Zia-ul-Haq, the ISI became the key conduit for US and Saudi support to the Mujahideen fighting Soviet forces in Afghanistan.

This Cold War era support, while initially seen as strategic, planted the seeds of a sprawling jihadist network. The ISI, flush with funds and international cover, began shaping and deploying these militant assets far beyond Afghanistan’s borders.

ISI’s Militant Network: Lashkar-e-Taiba and Jaish-e-Mohammad

Among the most notorious ISI-backed groups are Lashkar-e-Taiba (LeT) and Jaish-e-Mohammad (JeM), both responsible for devastating terrorist attacks in India. These groups have long served as the ISI’s covert strike arms, giving Pakistan plausible deniability while advancing its geopolitical agenda.

LeT’s 2008 Mumbai Attack: Perhaps the most infamous example of ISI-backed terrorism was the 26/11 Mumbai carnage, in which 166 people, including foreign nationals, were killed. Multiple investigations and confessions have established ISI’s direct control over LeT’s planning and execution of the attack, with Pakistani handlers giving real-time instructions to the attackers via satellite phones.

JeM and the Pulwama Attack: In 2019, a JeM suicide bomber killed 40 Indian paramilitary personnel in Pulwama, Jammu and Kashmir. The attack, which escalated tensions between India and Pakistan to the brink of war, bore the signature of ISI’s long-term strategy: using jihadi groups to provoke and destabilise while maintaining a facade of state detachment.

ISI’s patronage of these groups includes training camps, safe havens, financial support, intelligence guidance, and diplomatic cover. These organisations, in turn, have inflicted massive civilian casualties and stoked communal tensions across India.

Afghanistan: The Graveyard of Peace

ISI’s meddling in Afghanistan is equally destructive. For decades, the agency supported the Haqqani Network, a UN-designated terrorist organisation known for high-profile attacks on Afghan and NATO forces. Former Afghan President Hamid Karzai, and more recently, US officials, have consistently accused ISI of being the “hidden hand” behind Taliban offensives.

Even after the US withdrawal and the Taliban’s return to power in 2021, ISI’s influence remains strong. Many of the Taliban’s current leaders, including members of the Haqqani faction, have long-standing ties to the ISI. This has further alienated regional players and raised concerns about Afghanistan becoming a hub for global jihad once again.

The Humanitarian Fallout

The ISI’s proxy war doctrine has not only killed thousands of civilians and soldiers but also destabilised entire regions.

In India, cross-border terrorism has claimed the lives of over 14,000 civilians and security personnel in Jammu & Kashmir since the 1990s. The psychological trauma, displacement, and communal polarisation caused by ISI-sponsored violence continue to burden the Indian state and society.

In Afghanistan, the human cost has been staggering: hundreds of thousands killed over decades, millions displaced, and an entire generation deprived of education and healthcare due to prolonged conflict. The ISI’s role in prolonging the Afghan war for strategic depth has drawn widespread international condemnation.

Within Pakistan itself, the policy of nurturing terrorism has backfired. Blowback from “good” and “bad” Taliban factions has resulted in over 70,000 deaths, including the horrific 2014 Army Public School massacre in Peshawar, where over 140 children were slaughtered by Tehrik-i-Taliban Pakistan (TTP), a group with historical links to ISI-trained networks that later turned rogue.

Suppressing Democracy and Silencing Dissent

Beyond its cross-border operations, ISI plays a central role in Pakistan’s internal affairs: rigging elections, silencing journalists, intimidating civil society, and influencing judicial decisions. From the ousting of Prime Minister Nawaz Sharif to the media blackouts of dissenting voices, the ISI acts as the enforcer of Pakistan’s military-led deep state.

Recent power struggles between the military establishment and former Prime Minister Imran Khan also underscore how ISI functions as a political instrument, manipulating narratives, discrediting opponents, and ensuring military dominance over civilian rule.

A Radicalised Intelligence Wing and Global Risk

What makes the ISI particularly dangerous is the increasing radicalisation within its own ranks. The blurring of lines between intelligence operatives and jihadi sympathisers has created a volatile ecosystem where non-state actors operate with near impunity. Western intelligence agencies have repeatedly warned about ISI’s links to terror cells with global aspirations, including those capable of threatening Western targets.

This raises serious concerns not only for regional neighbours but also for global powers engaged in counterterrorism and peacekeeping. As the ISI continues to operate as both puppeteer and patron of extremism, its unchecked power remains a critical blind spot in South Asia’s security architecture.

The Case for International Accountability

At 77, the ISI has outgrown its intelligence role to become a regional menace. Its legacy, marked by terror sponsorship, democratic subversion, and humanitarian catastrophes, demands global attention.

Mere diplomatic pressure is not enough; targeted sanctions, international scrutiny, and a collective regional response are essential to dismantle the terror ecosystem nurtured by Pakistan’s spy agency. Until then, the ISI will continue to haunt South Asia: not as a guardian of national interest, but as a shadowy force destabilising the subcontinent from within.