India and Pakistan summon envoys after warships touch in the Arabian Sea

India summoned Pakistan's chargé d'affaires, Saad Ahmad Warraich, on 16 September. Pakistan summoned India's chargé in Islamabad the same day. Both protests concern a collision the previous evening in the north Arabian Sea, about 220 kilometres east of Oman and about 120 nautical miles from the Gulf of Oman.

Neither foreign ministry named the ships in its first on-record note. Indian and Pakistani briefings, and later a Pakistani statement, filled in the hulls. The Indian ship was INS Kolkata, a Kolkata-class guided-missile destroyer of about 7,400 tonnes, commissioned in 2014. The Pakistani ship was PNS Hunain, a Yarmook-class offshore patrol vessel of about 2,600 tonnes and 98 metres, commissioned the same year. Visuals released in Pakistan showed a dent in Hunain's hull. Indian sources said Kolkata took no serious damage and stayed on task. Hunain returned to harbour.

The accounts diverge on almost every other point.

India's Ministry of External Affairs said the Indian warship was on "routine surveillance" in international waters when a Pakistani unit closed at high speed and manoeuvred in an "unacceptable and unprofessional" way. The ministry said the conduct broke Article 10 of the April 1991 Agreement on Advance Notice on Military Exercises, Manoeuvres and Troops Movements. That article tells each navy to keep at least three nautical miles from the other's ships and submarines in international waters. Warraich was told to take that message home.

Pakistan's Foreign Office said the Pakistan Navy was running its biennial exercise SEASPARK-26 inside Pakistan's exclusive economic zone. It identified the Indian ship as INS Kolkata and said the destroyer had been trying to enter the exercise box since 7 September. On the 15th, Islamabad said, Kolkata changed course in a way that produced contact after Hunain tried to evade. A Pakistani security source said an Indian helicopter from the destroyer had also probed the box.

The last time the two navies touched steel was 2011, when PNS Babur brushed INS Godavari in the Gulf of Aden and damaged a helicopter safety net. The last time the two countries fought was 16 months ago, a four-day exchange of missiles and drones that ended in a ceasefire. That memory is why a dented patrol ship now produces demarches.

Warships carry radar, AIS and radio. They do not drift into each other in open water unless one commanding officer accepts a close pass. Indian commentators compared the run to Chinese shouldering tactics in the South and East China Seas. That comparison is an argument, not a finding. What can be said from the tonnage is narrower. A 2,600-tonne patrol ship that crosses a 7,400-tonne destroyer's bow takes the worse of the physics. That is what the photographs show.

The 1991 agreement exists precisely because the two navies share crowded water and a habit of surveillance. Article 10 is a distance rule, not a verdict. If the contact happened inside Pakistan's EEZ during a notified exercise, Pakistan will lean on that geography. If it happened in waters India treats as high seas, India will lean on the three-mile rule. EEZ status does not by itself ban another navy's innocent passage. It does raise the cost of a close pass during a live exercise.

No sailor is reported dead. No missile left a rail. The file now sits with two foreign ministries and two naval staffs that have not spoken easily since last year's fighting. The useful test is whether either side files a written notice under the 1991 accord, or whether the next exercise season begins with the same silence and a shorter fuse.