The Australian Labor Party's (ALP) National Conference todayis discussing the issue of Labor maintaining the preceding Morrison Government's AUKUS nuclear powered submarine proposal.
What distinguishes the conventional diesel-electric submarine force that Australia has now from the proposed Virginia and SSN-AUKUS nuclear powered submarines is speed, virtually unlimited range and ability to operate in Chinese and Russian waters.
Australia's future nuclear powered attack submarines (SSNs) be they Virginias (from the 2030s) and later SSN-AUKUS (from the late 2040s) do not need to be nuclear armed to engage in their principle functions which are engaging in nuclear warfare and to support the US in its long range conflicts.
The highest functions of US and UK SSNs and later Australian SSNs (even if not nuclear armed) are/will be to:
1. destroy Chinese and Russian nuclear missile carrying submarines (SSBNs) which can cruise at around 15 knots fully submerged, and
2. to protect US and UK SSBNs.
Only if Australian SSNs are fast and long range enough will they be able to achieve functions 1. and 2., and
3. to destroy even faster Chinese and Russian SSNs.
Australia carrying out the highest functions of its SSNs (nuclear war fighting) will invite a nuclear weapon response from China and Russia that only the US can protect us from.
Australia's greatly increased AUKUS submarine "premium" on the US nuclear deterrent "insurance policy" also involves US insistence that Australian SSNs will back up US forces in any US long range conflicts such as Taiwan, wider wars with China or Russia, or in the Middle East.
The US has noticed that Australia's conventional submarines, including the Collins have been too slow (cruising at around 4 knots fully submerged) and short ranged to get involved in US wars in the Middle East or other largely offensive wars. Australia's conventional submarines have been and still are useful for around 90% of Australia's mainly short-medium range defensive functions.
Australia, after buying US made Virginias and mainly UK made SSN-AUKUSs for what is more likely A$500 Billion (all up purchase and use), will at last be able to join Australian soldiers, airmen and surface ship sailors in fighting US led long range wars.
Australian unions should be aware that the vast bulk of Australia's purchase price for the Virginias is already going to US industry, with many $Billions to follow.
More than 50% of the purchase price of UK designed SSN-AUKUSs is likely to go to UK industry. This is mainly for the rear reactor half of the submarines, which for safety and UK labour expertise, will be completely built in the UK and perhaps shipped to Australia. The front half of the SSN-AUKUSs will only be assembled in Australia, mainly using UK and US made parts, then perhaps shipped to the UK for joining up with the reactor half.
Marles, being only a part-time defence minister, is not across these issues.