The Royal Australian Air Force has made a commitment under its Plan Jericho transformation to build an ‘‘all fifth-generation force’’ with the F-35A as a core capability through to the 2040s.

The RAAF’s first two of a total of 72 Lockheed Martin F-35A joint strike fighters (JSFs) are due in the country in December.

But the F-35A need not necessarily be the end of the story for the next 20 years. The air force needs to avoid limiting itself to the JSF as the ‘‘one solution that solves all’’ operational problems. It’s a highly advanced and capable platform, yet it’s taken a long time to mature, and our adversaries haven’t stood still. The RAAF will increasingly have to struggle to maintain an air advantage and could be flying in stormier skies in coming decades.

A key early decision to be made is whether to replace the 24 Boeing F/A-18F Super Hornets with an additional squadron of F-35As later next decade. The air force would be wise not to rush to such a decision, when an alternative option of upgrading the F/A-18F to what is known as Block III standard (along with upgrading the Growler to Advanced Growler) is available.

The F/A-18Fs remain a viable and effective capability for considerably longer than the proposed 2030 replacement date. Boeing’s proposed upgrade program would further extend their life of type to 9000 hours, as well as give them much more capable sensors, data systems and avionics comparable to those in the F-35’s advanced cockpit, but with considerably greater payload.

Cost is also a factor. A new squadron of 28 F-35s would cost $US2.24 billion (about $3.1bn) in 2018 dollars, not including sustainment costs. Upgrading our Super Hornets and Growlers would set the government back $US576 million. That’s a saving of $US1.66bn, and that could then be invested in a number of ways.

First, the RAAF could opt to have a larger air-combat force, buying 20 additional Block III Super Hornets. Quantity has a quality of its own, and betting all on JSFs has its risks. Adversary counter-stealth developments are sure to challenge and ultimately narrow the edge that stealth offers. Betting all on that edge remaining through to the 2040s is playing a losing hand. It might be better to diversify with a larger and upgraded Super Hornet and Growler force alongside the 72 F-35As.

Alternatively, the savings gained by going down an upgrade of the Super Hornets and Growlers could be applied to fund other much needed capability.

Another option would be that the air force acquire longer-range standoff weapons that can be carried on the Super Hornet and F-35A. These would include the long-range anti-ship missile (LRASM), and the proposed joint air-to-surface stand-off missile — extreme range (JASSM-XR) with a range of 1000 nautical miles.

Given the emerging threat environment, long-range platforms should be a much higher priority for the air force than now. We must break out of the dated air-sea-gap mindset, and instead increase forward strategic depth by embracing longer-range strike capabilities or even forward basing.

The Defence Department should also start thinking soon about future capabilities that could initially complement, and then replace, the F-35A and explore when that might happen. The F-35A is planned to fly through to the 2040s and, given regular modernisation, there’s no reason it can’t be a credible capability over its life of type.

But Australia shouldn’t ignore future concepts and capabilities now starting to enter development, which could add greater punch and reach for forces.

The US is undertaking work on the penetrating counter-air capability that could be a mix of manned and unmanned systems, operating in the air, in space, and through cyberspace. European projects such as Britain’s proposed Tempest and the Franco-German Future Combat Air System suggest a similar path of manned-unmanned teaming.

These are important projects to watch and, potentially, participate in, in a manner similar to our involvement with the JSF. So a future RAAF strike and air combat capability might see unmanned combat air systems (UCAS) reduce risk to manned fighters in highly contested air environments, characterised by advanced counter-stealth and electronic-warfare capabilities, long-range air-to-air and surface-to-air missiles, and advanced multirole combat aircraft, such as China’s Su-35 and J-20.

We should move away from a like-to-like replacement mindset, which would see the fifth-generation F-35A replaced in the 2040s with limited numbers of very costly and exquisite, but similar, sixth-generation platforms. Instead, Australia must develop strategic air power that contributes to building forward strategic depth in the South China Sea, the Indian Ocean and the South Pacific.

That means long-range platforms that can deploy forward and control swarms of low-cost unmanned combat air systems which then fly into harm’s way, or launch long-range standoff weapons. That future RAAF capability should deepen integration of space, cyber and electronic warfare into a true multi-domain operational concept, where the effects generated may not be purely in the air, or necessarily from the air.