For many years India has had an overall superiority in conventional submarine numbers (currently around 16 active boats mainly Kilo and HDW 209 developments) but India’s forces have diverse responsibilities - to cover several countries and broad sea areas. India's diverse missions might include:
- multi-mode intelligence collection off the coasts of Burma and Pakistan
- protecting India sea lines of communication (SLOC) (particularly oil), and
- preparing to interdict China’s oil routes across the Indian Ocean.
Pakistan has a total of five active diesel electric submarines These include:
- 3 Agosta 90B class submarines (PNS/M Khalid, Saad and Hamza). Hamza (see naval-technology) is equipped with the MESMA AIP. Khalid and Saad will be upgraded with the same AIP system from 2011, and
- 2 Agosta 70s (PNS/M Hasmat and Hurmat).
Pakistan also has 3 or 4 Italian-designed MG110 midget submarines for special forces insertion but perhaps also for one way suicide bombing missions in key harbours like Mumbai.
Pakistani submarine forces probably concentrate almost exclusively on India including, preparing to:
- defend the main port of Karachi;
- breakup an Indian blockade of Karachi and Gwadar
- attack shipping outside Mumbai’s large port area (representing 40% of India’s maritime trade), and
- active signals intelligence collection and possible agent dropping along India’s west coast.
These conventional roles may have remained little changed for decades but what is altering the strategic environment is India’s recent launch of its first locally designed submarine, INS Arihant along with India’s likely deployment of nuclear tipped, submarine launched BrahMos cruise missles and then K-15 ballistic missiles.
Furthermore Pakistan would wish to counter India's the nuclear capable 3M-54/Klub (or Club)/Sizzler cruise missile (further description). Russia has modified at least five of India's ten Kilo submarines to take this missile. While the missile is principally anti-shipping it can also be used for land attack out to 275km.
In response Pakistan is developing nuclear land attack missile options - perhaps in the medium term a naval variant of the Pakistani developed Babur cruise missile. The Babur has a range of 700 km and is capable of carrying 300kg conventional or nuclear warheads - all probably sufficient for Pakistan at the moment. The problem is that Barbur is probably too long, at 7m (with a booster rocket for submarine launch) to fit in an Agosta's current torpedo tube setup and too long for vertical launch (Agosta's have a 5330mm diameter. Modification to the Agosta torpedo tubes (unless done already) and test firing are necessary - this takes time. Hence Barburs may not be the easy, rapid fix Pakistan's Daily Times hopes for .
Pakistan probably realises that modification of the Exocet and Harpoon cruise missiles already on the Agostas may offer a quicker, but only partial solution. All of the Pakistani SSKs have been equipped with anti shipping cruise missiles which could conceivably carry nuclear warheads. The main problem is lack of range and miniturisation of nuclear warheads. The three Agosta 90B-Khalid class boats Exocets (165kg warhead) and two older Agosta 70-Hasmat’s wired to fire Harpoons (221kg warhead). See comparative chart on ASMs/cruise missiles. The smaller size of the warhead may limit their yield (unless Pakistan has thermonuclear warheads available). In any case their range (Harpoon is the longer range missile of the two - at 280km) is insufficient to hit Delhi from the sea in a second (final revenge) strike scenario and it would probably be a long, dangerous voyage to hit India's east coast targets.
Pakistan is known to have conducted tests on its anti-ship Harpoons to make them more land attack worthy. These tests may have also involved range extension.
In mid-2006 the Pakistan Navy announced its requirement of three new SSK attack submarines to replace the two Agosta-70s. The French naval firm DCN had offered its latest export design - the Marlin SSK - which [is an AIP equipped development of] the Scorpene SSK, but also uses technology from the Barracuda nuclear attack submarine. However, the Pakistan Navy is said to have chosen the German [AIP equipped] HDW Type 214 submarine. During the IDEAS 2008 exhibition, the HDW chief Walter Freitag stated “The commercial contract has been finalised up to 95 per cent.”
Pakistan, perhaps for bargaining reasons, has denied that a purchase of 3 HDW boats is final. To further complicate the purchasing picture, with France due to assist Brazil to build a nuclear Scorpene Pakistan may see possibilities for future French nuclear assistance.
Pakistan would certainly be worried about India's development of nuclear submarines with nuclear missiles yet the cost and lead times for Pakistan itself to develop its own nuclear submarines would be too great. Assistance from France or even China is likely to be too politically charged from a proliferation standpoint. In any case nuclear propulsion may not be an essential requirement for 3 or 4 Pakistani submarines. Adequate medium range nuclear tipped missiles fired from sufficiently large conventional submarines may be what Pakistan wants or needs.
Therefore it will be of great interest what submarine Pakistan wants next, including subsequent diameter alterations, VLS choices or further testing of appropriately sized cruise and ballistic missiles.