India-Pakistan relations: conflict, terrorism and the limits of engagement

No bilateral relationship consumes Indian foreign policy like Pakistan. Two wars within eighteen years of Partition, a third in 1971, a fourth at Kargil, and a near-continuous terror campaign since the 1990s have made the western border India's permanent security preoccupation. As Shivshankar Menon put it, India's approach has oscillated between optimism for peace and realism about security, and the optimism has never lasted.

The exam treats this relationship as three problems braided together: contested territory, cross-border terrorism, and a nuclear overhang that punishes escalation. Understand how the three constrain each other, and the ceasefire lines, treaty texts and strike doctrines all fall into place.

Partition's unfinished file: the territorial core

The dispute was born in October 1947, when a tribal invasion pushed Maharaja Hari Singh to sign the Instrument of Accession in exchange for Indian military aid. The 1948 war froze the first ceasefire line. Pakistan's 1965 attempt to alter Kashmir by force ended with the Tashkent Agreement; the 1971 war produced the Shimla Agreement of 1972, which made bilateralism the declared basis of dispute resolution. India secured the Saltoro heights in 1984 through Operation Meghdoot, and the 1999 Kargil intrusion showed that civilian diplomacy in Lahore could not restrain the Pakistan Army.

The boundary itself is a layered system, not a single line. The International Border runs from Gujarat to Jammu; the Line of Control, formalised by Shimla, is a military control line rather than a recognised frontier; the Actual Ground Position Line extends from NJ9842 across Siachen; and the 110-km Sir Creek strip in the Rann of Kutch is undemarcated, with India claiming a mid-channel boundary under the thalweg principle and Pakistan claiming the whole creek.

Terrorism: the relationship's central fact

What began as Kashmir militancy in the 1990s hardened into an infrastructure of groups like Lashkar-e-Taiba and Jaish-e-Mohammed operating from Pakistani soil. The 2008 Mumbai attacks froze the composite dialogue; the 2016 Pathankot and Uri attacks drew India's first declared surgical strikes across the LoC; and the February 2019 Pulwama bombing was answered by the Balakot airstrike, the first use of air power across the border since 1971.

The doctrine has visibly shifted. Strategic restraint gave way to punitive deterrence: strikes are now public, owned and calibrated. The 2021 reaffirmation of the 2003 LoC ceasefire quietened the guns, but it froze politics rather than reviving it, and "terror and talks cannot go together" became the operating rule.

Pahalgam and Operation Sindoor: the 2025 turn

The April 2025 Pahalgam attack, which killed 26 civilians and was attributed by India to Pakistan-backed groups, triggered the sharpest response cycle since Kargil. India placed the Indus Waters Treaty in abeyance and launched Operation Sindoor: precise, restrained tri-services strikes on terror infrastructure, notable for the first operational use of loitering munitions and high Army-Navy-Air Force synergy.

Delhi framed the operation as lawful self-defence under Article 51 of the UN Charter and pointedly rejected any third-party mediation, reinforcing strategic autonomy. The message was aimed as much at the future as at the present: sponsoring terror infrastructure would invite direct, focused retaliation, and the era of absorbing attacks for the sake of dialogue was over.

The water lever: the Indus Waters Treaty

Signed in 1960 with World Bank brokerage, the treaty gave India unrestricted use of the three eastern rivers (Ravi, Beas, Sutlej) and Pakistan the bulk of the three western rivers (Indus, Jhelum, Chenab), with limited Indian rights for agriculture and run-of-the-river hydropower. Roughly 80 percent of the system's water was apportioned to Pakistan. A three-stage dispute mechanism runs from the Permanent Indus Commission through a neutral expert to a Court of Arbitration.

Friction was built in. Pakistan has repeatedly objected to Indian projects such as Kishanganga and Ratle on the Jhelum and Chenab, and the dispute over those projects produced the anomaly of a neutral expert and a Court of Arbitration proceeding simultaneously, which India argues violates the treaty's sequencing. India had also invoked Article XII(3) to seek a review, citing demographic change, environmental stress and clean-energy needs.

The 2025 abeyance exploits a legal grey zone. The treaty has no unilateral exit clause: Article XII(4) requires mutual agreement to terminate. India's justification leans on the "fundamental change of circumstances" principle, Article 62 of the Vienna Convention on the Law of Treaties, recognised as customary international law. "Abeyance" rather than termination keeps the legal file deliberately ambiguous.

The nuclear shadow

Both states declared nuclear weapons in 1998, and Kargil a year later proved that the bomb does not prevent limited war; it only changes its grammar. Every crisis since, from the 2001-02 standoff to Pulwama-Balakot, has been an exercise in signalling under the nuclear umbrella, with the international community pressing de-escalation and India insisting on its right of response.

The doctrines do not mirror each other. India holds a no-first-use posture; Pakistan leans on full-spectrum deterrence with tactical weapons, which lowers the threshold rhetoric. The thin safety net is crisis communication: DGMO hotlines, backchannels and the 2021 ceasefire understanding.

Why engagement keeps hitting the same ceiling

Four ceilings recur. First, the civil-military gap in Pakistan: the Lahore Declaration of 1999 was followed within months by Kargil. Second, Kashmir internationalisation: Pakistan seeks third-party mediation while India, citing Shimla, accepts only bilateral talks. Third, the China-Pakistan axis: CPEC passes through Pakistan-occupied Kashmir, which Delhi reads as an affront to sovereignty, compounded by Pakistan's 2020 move toward provisional provincial status for Gilgit-Baltistan.

Fourth, the economics and institutions of hostility. India revoked Pakistan's Most Favoured Nation status after Pulwama in 2019; trade is near zero. South Asian Association for Regional Cooperation (SAARC) is, in S. Jaishankar's phrase, a jammed vehicle. Afghanistan has become a third theatre of competition, with Pakistan's quest for "strategic depth" colliding with India's development footprint.

The Kartarpur Corridor is the one durable opening: the visa-free corridor opened in 2019 letting Sikh pilgrims visit Gurdwara Darbar Sahib in Pakistan's Narowal district. It is the textbook case of low-politics, people-to-people contact surviving high-politics hostility, and examiners cite the 'Kartarpur model' for heritage-based engagement such as Sharda Peeth.

The fine print: Siachen, Sir Creek and the OIC

Beyond Kashmir and terrorism, three files keep resurfacing in the bilateral story: Siachen, Sir Creek and the multilateral stage where Pakistan lobbies against India. The Siachen Glacier file is a study in near-misses: the Line of Control could never be demarcated beyond point NJ9842 because of the terrain and weather, and India and Pakistan came close to an agreement on the glacier three times, in 1989, 1992 and 2006, without closing the deal. The human cost is measured in weather, not war: as many as 167 Indian Army personnel lost their lives on Siachen in a decade, almost all to weather-related incidents.

Sir Creek is a 92-kilometre marshy estuary separating Gujarat from Sindh, and the dispute is about where the maritime boundary runs. India's position is that the boundary lies mid-channel, as depicted in a map drawn in 1925, with mid-channel pillars installed back in 1924 supporting that reading.

The Organisation of Islamic Cooperation (OIC), comprising 57 member states, represents the collective voice of the Muslim world and seeks to protect their interests on the global stage. Although India is home to one of the world's largest Muslim populations, it is not a member, largely because of Pakistan's opposition. The OIC has frequently issued statements on Jammu and Kashmir that align with Pakistan's narrative, which India rejects as interference in its internal affairs; its statements after Operation Sindoor in 2025, alleging human rights violations against Muslims, continued that trend. India has meanwhile deepened ties with key OIC members like Saudi Arabia and the UAE, managing the bilateral track even amid multilateral criticism.

Why this is in the news: the abeyance of the Indus Waters Treaty has set a precedent that examiners will link to every other water file in the neighbourhood, and the 1996 Ganga Treaty with Bangladesh, up for renewal in 2026, is the next one to watch.

India-Pakistan at a glance

What examiners keep asking

• Structure every answer on the three-braid thesis: territory, terrorism, nuclear overhang; each constrains the other two.
• The IWT abeyance is the standard "water as leverage" answer: know the eastern-western split, the dispute mechanism, and the Article 62 legal argument.
• For "why no peace" questions, list the ceilings in order: terror infrastructure, civil-military gap, Kashmir internationalisation, China-Pakistan axis.

Key Terms

• Organisation of Islamic Cooperation (OIC): The Organisation of Islamic Cooperation (OIC), comprising 57 member states, represents the collective voice of the Muslim world and seeks to protect their interests on the global stage. India is not a member, largely because of Pakistan's opposition.
• The Kartarpur Corridor is: The Kartarpur Corridor is the 4.7 km visa-free border crossing opened on 9 November 2019 connecting Dera Baba Nanak in Indian Punjab to Gurdwara Darbar Sahib in Pakistan's Narowal district, the final resting place of Guru Nanak. It allows pilgrims to visit the shrine without a visa, and was opened for the 550th birth anniversary of the Guru. It matters because it is a rare India-Pakistan confidence-building measure and a staple UPSC international relations and Sikh-history current-affairs topic. opened 9 November 2019
• Permanent Indus Commission: The Permanent Indus Commission is the bilateral body set up under the Indus Waters Treaty of 1960 between India and Pakistan. Comprising the Indus commissioners of both countries, it meets at least once a year, alternately in each country, to exchange data and resolve questions on the treaty's implementation before disputes escalate. For UPSC it is the core institution in India-Pakistan water questions and a classic example of treaty-based cooperation. The 116th meeting of the Commission in New Delhi in March 2021
• Court of Arbitration: A court of arbitration is a tribunal set up to resolve disputes through arbitration rather than litigation, typically under agreed rules and with an arbitrator chosen by the parties or an administering institution. Awards are generally binding and enforceable like court decrees, and the process is prized for speed, confidentiality, and expertise. For UPSC it matters in governance and IR, covering investor-state disputes, commercial contracts, and India's reforms aimed at making the country a preferred arbitration venue.
• Most Favoured Nation: Most Favoured Nation is a World Trade Organization principle, codified in GATT Article I, requiring a member to extend any trade concession, tariff cut, or privilege granted to one trading partner equally to all WTO members. It is the legal expression of non-discrimination in global trade, with limited exceptions for free-trade areas. For UPSC, MFN is central to economy and international-relations preparation, and India's 1996 grant and 2019 withdrawal of MFN status to Pakistan make it current-affairs relevant. India withdrew MFN status to Pakistan after the 2019 Pulwama attack
• Indus Waters Treaty: The Indus Waters Treaty is the 1960 India-Pakistan agreement brokered by the World Bank that divides the six Indus-system rivers, assigning the eastern rivers (Ravi, Beas, Sutlej) to India and the western rivers (Indus, Jhelum, Chenab) to Pakistan, with limited Indian rights on the western rivers. It has survived multiple wars between the signatories. For UPSC it is the canonical case study of transboundary water sharing.
• Line of Control: The Line of Control is the 740-km military control line dividing Indian and Pakistani administered areas of Jammu and Kashmir, originally the 1949 Ceasefire Line and renamed under the 1972 Shimla Agreement. It is not an international border, and infiltration and ceasefire violations along it shape India-Pakistan relations. UPSC tests it in GS-2 and security questions on Kashmir, the Shimla Agreement, and border management. the 1972 Shimla Agreement, which renamed the Ceasefire Line
• full-spectrum deterrence: Full-spectrum deterrence is Pakistan's nuclear doctrine, adopted by its National Command Authority in September 2013 to replace minimum credible deterrence. It seeks deterrence at every level of threat, from tactical to strategic, including battlefield nuclear weapons meant to counter India's conventional superiority and Cold Start posture. For UPSC (GS-3, security), it explains South Asia's nuclear stability-instability paradox and crisis escalation risks. Pakistan's Hatf-IX (Nasr) short-range nuclear-capable missile, first tested in 2011
• cross-border terrorism: Cross-border terrorism is terrorist violence that is planned, directed, financed or sheltered from across an international border, distinguishing it from purely domestic insurgency. In India's usage it describes Pakistan-based groups such as Lashkar-e-Taiba and Jaish-e-Mohammed operating against India with state sponsorship. For UPSC it is a core internal-security theme, appearing in questions on Kashmir, surgical strikes, FATF grey-listing and India's counterterrorism diplomacy. The November 2008 Mumbai attacks, planned and launched from Pakistan.
• punitive deterrence: Punitive deterrence is India's post-2016 strategic doctrine toward Pakistan: after Uri, Pathankot and Pulwama moved India from restraint to punitive deterrence, strikes became public, owned and calibrated, as answered by the Balakot airstrike, the first use of air power across the border since 1971.
• Strategic restraint: Strategic restraint is a deliberate policy of limiting one's own use of force or escalation despite provocation, to avoid wider conflict. In the Indian context it describes the post-independence approach of measured responses, a no-first-use nuclear pledge and credible minimum deterrence. For UPSC, it is a staple GS-3 and IR concept for answers on national security doctrine, deterrence and crisis management. India's no-first-use pledge in its nuclear doctrine (draft 1999)
• composite dialogue: The composite dialogue is the structured India-Pakistan peace process in which all outstanding issues, Kashmir, Siachen, Sir Creek, terrorism, trade, and people-to-people contact, are discussed simultaneously in eight baskets. Conceived at Male in 1997 and revived after the January 2004 Islamabad summit, it ran until the 26/11 Mumbai attacks of 2008. For UPSC, it is the key GS-2 reference for India-Pakistan relations and track-two diplomacy. The January 2004 Islamabad joint statement by Atal Bihari Vajpayee and Pervez Musharraf

Practice questions