The Pakistan Navy operates a fleet of five diesel-electric submarines and three MG110 miniature submarines (SSI).[1] Although these vessels are currently based at Karachi, it is possible that in the future some may also be based at Port Ormara.[2] The nucleus of the fleet comprises two Agosta-70 boats and three modern Agosta-90B submarines, all of French design. Pakistan's third Agosta-90B, the S 139 Hamza, was constructed indigenously and features the DCNS MESMA (Module d'EnergieSous-Marin Autonome) air-independent propulsion system (AIP). The two earlier Agosta-90B vessels will be retrofitted with the MESMA AIP propulsion system during their next major overhaul. [21]

The Agosta-90B Hamza (Khalid-class) was constructed at the Karachi Shipyard and Engineering Works (KSEW).[3] Pakistani officials and media outlets extolled the accomplishment, treating the indigenous submarine's 26 September 2008 commissioning as a significant step in the enhancement of the country's naval capabilities vis-à-vis India.[4,5,6] It is the first conventional submarine in the Indian Ocean to feature the AIP system (in this case a 200KW liquid oxygen MESMA AIP), which allows the vessel to increase its submerged endurance for up to 3 weeks and improves its stealth characteristics.[13, 15, 16]

During the 1971 war between India and Pakistan, India effectively blockaded the port of Karachi, Pakistan's only major harbor. In response, Islamabad was able to curtail India's naval supremacy only through the use of its submarine force, which sank one Indian frigate.[7] Drawing on these experiences and the perceived threat posed by a larger Indian Navy, Pakistan has been continuously investing in its submarine force, within the constraints posed by its economy.

An effective sea-denial capability is vital to Pakistan. Foreign trade is increasingly important to the country's economy, best illustrated by a trade to GDP ratio of 36.0 percent in 2007-2008.[8] Given that over 95 percent of this trade is seaborne, the Pakistan Navy and its submarine fleet is charged with protecting the country's sea lanes of communication (SLOC).

Developments in India's naval infrastructure and force posture significantly inform Pakistan's own naval planning. In February 2001, the Pakistan Navy publicly considered the deployment of nuclear weapons aboard its submarines, arguing that it had to keep pace with developments in India.[9] Islamabad later rescinded its statement in January 2003, reaffirming Pakistan's commitment to a "minimum credible deterrence."[10] However, in the wake of India's short-range Agni-I test that month, then Chief of Naval Staff Admiral Shahid Karimullah left the option open, saying that while the country had no plans to deploy nuclear weapons on their submarines, they would do so only if "forced to."[11,12] But most experts agree that Pakistan is, at the very least, attempting to develop a sea-based version of the indigenously built nuclear capable ground-launched cruise missile 'Babur'. [13] This missile is similar in design to the American Tomahawk and Russian KH-55 cruise missiles.[14]

In an attempt to further improve its naval capabilities, Pakistan has also been negotiating with Germany's ThyssenKrupp Marine Systems (TKMS) about the possible acquisition of three diesel-electric Type 214 submarines equipped with an AIP system based on fuel cell technology. Discussions regarding the deal have been taking place since 2004, but due to political developments in Pakistan as well as Germany, it has been repeatedly delayed. [17] In November 2009, the German Ambassador to Pakistan announced that a final decision would be made soon. [18] Parallel to the negotiations with TKMS, France has also been attempting to sell its Scorpene-class submarines to Pakistan. [19, 20]

Sources:
[1] "Chapter Seven: Central and South Asia Caribbean and Latin America", The Military Balance 2009, International Institute of Strategic Studies, Routledge, 2009.
[2] Interview with Vice Adm. Clees van Duyvendijk, Commander in Chief RNN, "Navy Chiefs of Staff on MCM and minelaying," Naval Forces, 2001, Vol. 22, No. 3, pp. 62-68; in ProQuest Information and Learning Company, http://proquest.umi.com.
[3] The Royal Institute of Naval Architects, Karachi Shipyard and Engineering Works retrieved on 28 January 2010 from www.rina.org.uk.
[4] "Pakistan navy inducts new submarine", Associated Press of Pakistan, 27 September 2008; in Lexis-Nexis Academic Universe, http://web.lexis-nexis.com.
[5] "India submarine 'threatens peace'", BBC News, 28 July 2009, http://news.bbc.co.uk.
[6] "Pakistan on verge of selecting HDW submarine", Jane's Defence Weekly, 2 December 2008, www.janes.com.
[7] "Bangladeshi War of Independence: Indo-Pakistani War of 1971", GlobalSecurity.Org, www.globalsecurity.org.
[8] "Economic Survey 2008-2009", Ministry of Finance, Government of Pakistan, www.finance.gov.pk.
[9] "Pakistan may install nuclear missiles on its subs", Los Angeles Times, 23 February 2001, www.latimes.com.
[10] "Pakistan to retain minimum nuclear deterrence, PM says", The News, 07 January 2003; in Lexis-Nexis, http://web.lexis-nexis.com.
[11] Catherine Philp, "India stokes the fires with new missile test", The Times, 10 January 2003, www.timesonline.co.uk.
[12] "Pakistan navy chief denies plan to equip submarines with nuclear warheads", The News, 26 January 2003; in Lexis-Nexis, http://web.lexis-nexis.com.
[13] Feroz Hassan Khan, Pakistan's Perspective on the Global Elimination of Nuclear Weapons, Report prepared for the Henry L. Stimson Center, April 2009.
[14] Ottfried Nassauer, Deutsche U-Boote fuer Pakistan: Fakten und Gedanken zu einem problematischen Exportvorhaben, Berliner Zentrum fuer Transatlantische Sicherheit, Research Note 8.1 (December 2008).
[15] "Agosta Class," Jane's Underwater warfare Systems, 25 September 2009.
[16] "MESMA," Direction des Constructions Navales Services, September 2008, www.dcnsgroup.com.
[17] Ottfried Nassauer, Deutsche U-Boote fuer Pakistan: Fakten und Gedanken zu einem problematischen Exportvorhaben, Berliner Zentrum fuer Transatlantische Sicherheit, Research Note 8.1 (December 2008).
[18] "German Parliament discussing approval for submarines," Business Recorder, 11 November 2009.
[19] "U-Boot Deal auf der Kippe," Der Spiegel, 30 April 2007.
[20] "Poker mit Pakistanern," Der Spiegel, 13 July 2009.
[21] "Pakistan Submarine Forces," Jane's Underwater Warfare Systems, 25 September 2009, www.janes.com.