India may feel more secure during Pakistan's low submarine availability, but China may be helping make up the difference. Of Pakistan's fleet of 5 (conventional Agosta) submarines Pakistan normally has 3 or 4 potentially available. But now Pakistan only has two available.
Drawing from this article of August 12, 2021:
3 of Pakistan's 5 Agostas are either being upgraded or have defects, making them unavailable.
Currently, only 2 Pakistani submarines are available till the middle of 2022,. These are:
- PNS Hamza an Agosta 90B (with MESMA AIP like the other 2 x 90Bs), and
- PNS Hashmat, a 42 year old Agosta 70 .
In contrast, those unavailable are:
- PNS Hurmat, an Agosta 70, with one of its 2 diesels broken and problems with its Electronic Warfare Support Measures system. This is not surprising as Hurmat is 41 years old.
- PNS Saad, an Agosta 90B submarine is in dry dock, being refitted until 2024. This is an extended period meaning Pakistan must have a very inefficient submarine overhaul system. The overhaul may permit use of Sea Hake torpedos and nuclear tipped Babur 3 cruise missiles, and
- PNS Khalid, another Agosta 90B is being refitted, with COVID-related delays.
China may only start delivering the first of the export variant S20 Yuan-class submarines to Pakistan in 2023-24.
India, in comparison, is better with:
- 3 new Kalvari class Scorpenes and 3 more to follow
- 4 Shishumar class Type 209s, and
- 8 Sindhughosh Kilo class submarines.
India also has:
- the small SSBN INS Arihant, currently armable with 12 small K15 SLBMs or 4 larger K4s in future.
and
- the one submarine India is gaining, INS Arighat (aka "S3") may be the same size as Arihant or slightly larger. It began harbour trials in 2020, may undertake sea trials later in 2021 and may perhaps be commissioned in late 2022. It may potentially carry 24 x K15s (available now) or 8 larger K4s in future.
What India lacks is any SSNs (may have some locally built in 12 years) which are essential to protect its SSBNs by searching for and countering Chinese SSNs. India did have an apparently unarmed Russian SSN, INS Chakra 2 for crew and maintainer training and technology transfer. Chakra 2 (ex Nerpa) was on 10 year lease and was seen apparently returning to Russia in June 2021.
But, in any case, one SSN is insufficient to protect an Indian SSBN, particularly when that SSBN is making predictable movements leaving or returning to India's current SSBN base at main Naval HQ East, Vishakhapatnam. At least 3 Indian SSNs are needed to counter an enemy SSN. This takes into account one SSN being overhauled, SSN tactics, the Arihant class likely being noisy and overall the Rule of Thirds.
Returning to Pakistan's 2 available subs. China is Pakistan's senior ally and more specifically the ally that is building new submarines forPakistan. China may be currently assisting Pakistan by deploying a Yuan class SSK (in Pakistani waters) and/or even an SSN (in those waters or maybe in the Bay of Bengal). This is while India is lulled into a false sense of security while Pakistan is in submarine deficit. China would dearly love to get a sub close to INS Arihant or Arighat to discern those Indian SSBN's audio signal profiles, other emissions, strategy and tactics.