This is no time to be thinking of jumping from the plan to build nuclear-powered attack submarines (SSNs) with Britain and into a doubtful alternative of constructing US Virginia-class boats in Australia.

Doing so would be to move from a plan with definite but understood risk to one that would have risks that haven’t been examined. Moreover, Britain’s commitment to developing the SSN-AUKUS design and building submarines of the class should not be doubted.

James Curran’s ‘Questioning AUKUS’ series in The Australian Financial Review launches a broadside against the $368 billion project amid claims that the ambitious plan ‘is a mess and risks leaving Australia with no submarine capability’. It reviews domestic construction of Virginias as a Plan B.

But the series of articles fails to present a catastrophic failing of the Optimal Pathway, the course of action which we’re following and which was identified as best by the three AUKUS countries.

There is risk, but managing risk is a key element of any complicated defence project and has been acknowledged upfront by the current and former governments, alongside Defence.

Two points in the Australian Financial Review series warrant immediate challenge. The first is the characterisation of the United Kingdom’s ability to support AUKUS and the second is the proposal of the so-called Plan B.

AUKUS is a critical project for the UK, and Australia needs the UK’s support for it to succeed. Curran is right to highlight the stresses on the UK submarine industrial base, and UK officials have consistently highlighted that the production of the country’s replacement ballistic missile submarines (SSBNs) is its priority, followed by AUKUS.

Currently, the UK operates four SSBNs commissioned during the 1990s. These submarines are critical to its defence strategy, as they are the sole arm of its strategic nuclear deterrent.

The UK’s ageing Vanguard-class submarines are being replaced by four Dreadnought-class vessels. The construction of three of the four is under way, and the first is expected to be operational in the early 2030s. Despite Curran’s assertion that the delivery timeframe has not been updated in six years and might have slipped, the 2022–23 UK Ministry of Defence annual report lists the Dreadnought program as on track for delivery in the early 2030s.

As much as the replacement of its nuclear deterrent is rightly the top priority for the UK, the AUKUS SSN is also crucial to the British nuclear strategy. To have a submarine-based nuclear deterrent capability, you need SSNs to protect it.

Not only is the UK’s AUKUS SSN, given its SSBN protection role, at the core of the country’s defence strategy, but also the partnership with the UK and Australia will alleviate some of the pressures on the British submarine industrial base. The significance here is that the UK is a deeply invested party to AUKUS Pillar 1, because that part of AUKUS is also at the core of the British defence strategy.

It is tempting to jump to the counterargument that there is nothing in this for Australia, and that it is being used to prop up the submarine industrial base of the UK. Not true. The UK is essential to Australia’s acquisition of nuclear-powered submarines for several reasons.

The UK was critical in convincing the US to allow the technology to be transferred, and its remains a critical balance to any changing US political whims. A bilateral arrangement for the transfer of nuclear-powered submarines is more easily abandoned than a trilateral one that includes an invested partner such as the UK. And let’s not forget that the UK’s nuclear deterrent is also a critical part of NATO’s deterrence strategy. The UK’s involvement in AUKUS complicates any potential future exit strategy by the US. Think of it as insurance.

Curran’s investigation series appears to promote a nuclear-powered submarine pathway Plan B. The point that is ignored in the platforming of a Plan B is that the Plan B carries with it greater risk than the Optimal Pathway. The Optimal Pathway has involved heavy consultation and has been agreed upon at the highest levels of government and defence in all three AUKUS partners. Its endorsement by all three partners is an important risk-reduction measure in itself.

The so-called Plan B, which relies on Australia being supported to build the United States’ close-hold Virginia class submarines in Australia within the next decade is untested and—based on Australia’s difficult journey of attempting to obtain a licence to produce US missiles under its Guided Weapons Enterprise—is simply unlikely to gain agreement and support in the near to medium term.

More importantly, although the Optimal Pathway is complex and hence unlikely to run exactly to plan, there is no evidence to date of a catastrophic failing of the pathway, nor the development of a level of extreme risk that cannot be managed.

That is not to say this won’t manifest in future. None of us has a crystal ball, but there is no such indication to date. Without a catastrophic failure of an element of the Optimal Pathway or the generation of an unmanageable risk level, any knee-jerk reaction of Australia to change the pathway within two years of its announcement would disastrously undermine confidence in its commitment to AUKUS Pillar 1 and probably drive its AUKUS partners to question its ability to support the ambitious project.

It is simply nonsensical to abandon without a reason or catalyst an agreed plan with known risk that is being treated and instead go for a plan that so far has not gone through a consultation process and would have significant risk.

Debate on AUKUS is important. Australia’s acquisition of nuclear-powered submarines will not go exactly to plan; you simply cannot predict the next 34 years. But right now, the risk is known, it appears that it is being managed, and all three partners have demonstrated their commitment to the process.

The measure of success here is not whether the Optimal Pathway hits every milestone exactly on time; rather, it is whether, 10 years from now, Australia is operating a nuclear-powered submarine capability. At present, there is no strong reason to believe this won’t be the case.