The strategic impact was even more significant as the Indian navy cancelled "Operation Triumph", the third missile attack, which was to be launched on 10 December.

[5] After the second war with Pakistan in 1965, the Indian Navy underwent a rapid modernization and expansion, causing the Pakistan Navy's focus to shift towards strengthening their existing Submarine Command (COMSUBS) due to being unable to acquire fighter jets from the Air Force.

[6] At midnight of 2/3 December 1971, Hangor, remaining submerged in a northerly direction, investigated radio transmissions intercepted from the warships belonging to the Western Naval Command of the Indian Navy that would launch a first missile attack on Karachi.

Tasnim broke the radio silence and communicated with the Navy NHQ to warn of the attack, but this message was intercepted.

[7] On 9/10 December 1971, at 19:00, Hangor detected the possible signature of the two Indian frigates dispatched in response to the intercepted communications.

Tasnim ordered Hangor to dive deep to carry out a blind (sonar only) approach as the torpedo team concentrated on tracking the two targets as they gradually came within firing range.

[8] As Kirpan fled the battle, Khukri, to its south, knowing the direction from which the torpedo had come, increased speed and came straight for an attack on Hangor.

[7] Kirpan returned to the scene next day to execute the rescue operation along with INS Katchal but left without success.

[9] After this incident, there was a massive search and destroy mission led by the Western Fleet, indiscriminately dropping depth charges hoping to sink Hangor.

Tasnim had Hangor submerged for almost a week, returning to its base with depleted lead batteries during the night of 13 December 1971.

[7] According to his personal admission in 2001, Tasnim maintained: "An extensive air search combined with surface ships made our life miserable but with the intelligent evasive action we managed to survive these attacks and arrived in Karachi safely after the ceasefire.