Since I wrote about B-21s on August 23, 2022 I've had some more thoughts.
The "Australia might be able to purchase the B-21" issue arose in mid August 2022. So, it may be no coincidence that an Air Chief Marshal(retired) Sir Angus Houston was appointed joint leader of the Australian Defence Strategic Review earlier that month. That review might produce an Interim Big Picture report by 1 November 2022 and Final Report, with recommendations, by 1 February 2023
Few performance specifications for B-21sare available, but it is assumed their specs will be equal to or greater than the B-2s, made by the same company, Northrop Grumman.
The major advantages of the B-21 might include:
They promise to be very stealthy. like submarines, but different.
Unlike submarines, they cannot be built in Adelaide or anywhere in Australia. So there is no twice the delay for twice the price, build in Australia, curse.
They might be in RAAF use by 2030 - "Initial Operating Capability [in the US] is expected to be reached by 2030."
B-21s would be ready for Australia far sooner than 3 of the last “LOTEd”Collins and Australian made Interim SSKs. B-21s might negate the need for 3 out of 6 Collins LOTEd Collins and Interim SSKs. This is especially if Anduril and/or Orca LDUUVs are used by the RAN - with LDUUVs doing many of the tasks of Collins and Interim SSKs.
The weapons load of a B-21 is very heavy and dual nuclear-conventional warhead capable. Only minimal software changes to Australian B-21s might need to be made to make them capable of long range nuclear strike.
As a major task of the B-21s would be as a deterrent to China it is significant that the distance from Alice Springs to Beijing is around 3,950nm. The range of the B-2 with one air-refuel is 10,000nm. This is sufficient for a B-21 based in central Australia just south of Alice Springs to hit Beijing even with free fall bombs and return. In any case a more likely internal weapons load is hypersonic air to surface missiles. An example is the ARRWhypersonic missile with a range of 870+nm.
“Tipped off” by fixed and mobile underseas sensors (including LDUUVs) B-21s would be useful stealthy naval strike platforms out to a longer ranges than SSKs based in Fleet Base West (Rockingham) or East (Sydney).
But there are some risks, including:
The B-21 may not get full US funding right through the production stage, even for USAF use.
B-21s may face technical delays of the enormity experienced with F-35s.
A risk whether the US would be prepared to sell B-21s to Australia in the first place. Hurdles are many. Hurdles might include a change to a US President (in 2024-5) with a less generous outlook than Biden (of AUKUS), US Departments of State and Defense restrictions, years being held up in the US Congress and B-21 makers posing problems.
The B-21 Project and Unit price for Australia may be very high as B-21s are up there with F-22s in stealth features and maintenance costs. There is no US track record of the US selling nuclear capable heavy bombers to foreign customers – so no guidance on profit margins, etc.
Price for Australia would be highly dependent on number of B-21s built for the USAF. The B-2s for the USAF each cost around US$4 Billion (in 2022 US dollars) because numbers produced declined from 132expected to 21 actually produced. Production expectations for the B-21 have dropped from 200 to perhaps 100 or maybe 80 and still being calculated.
Australian B-21s may less useful in having export stealth specs lower than top specs for USAF B-21s.
In a conflict with China even B-21s based in central Australia might be "taken out" on the ground in a Chinese ballistic or hypersonic missile surprise attack.
Decades of technical innovations and siting of distributed radars on Chinese bases in the Solomons, South China Sea islands, on intercept ships, UAVs and satellites might reduce the stealth invisibility of Australian B-21s. So Australian B-21s and F-35As (for that matter) might be detected and shot down in time of conflict.
Even spies on ground near a stealth aircraft base might be instrumental in detection and shooting down of stealth aircraft.
Conclusion
Anyway, despite the above, Australian B-21s might make an impact sooner than submarine delays in posing a deterrent against China.