The evolution of combat drones is likely to be so rapid over the next decade that Australia might buy them instead of some Joint Strike Fighters, the Chief of the Defence Force has said. 
The Defence white paper, released last week, states that Australia will buy 72 Joint Strike Fighters to replace current fighter planes the Classic Hornets, six of which are now flying bombing raids over Iraq and Syria.
But it leaves open the possibility of not buying a final squadron of roughly 25 JSFs to make up the roughly 100-strong air combat fleet Australia needs.
Instead, the paper states that to replace the newer current squadron of Super Hornet aircraft from about 2030, alternatives will be "considered ... in light of developments in technology and the strategic environment and will be informed by our experience in operating the Joint Strike Fighters".
Asked during a briefing on the white paper what Defence was planning, Air Chief Marshal Mark Binskin - himself a fighter pilot - said it was keeping an "open mind", given the rapid improvements in armed drones or "unmanned combat aerial vehicles".
"We're going to be open-minded because if you go ... say 10 years between now and when we consider [the next planes] ... you are starting to see the evolution of the UCAVs, unmanned combat aerial vehicles. So I think we need to keep a bit of an open mind.
"We shouldn't just lock in and say 'That's the way it's going to be for 50 or 100 years'."
The JSF, which is highly advanced but has been beset by delays and niggling flaws, is known as a "fifth-generation" aircraft, relying heavily on stealth and its ability to see the enemy at great distances so that it never has to get into a direct fight.
Asked if the next generation would be unmanned, Air Chief Marshal said: "I wouldn't say the whole generation ... But I think we need to ... look at the capabilities."
Unmanned systems are increasingly being seen as the future. within military circles.
These include maritime assets such as submarines.
Australia's next submarines are likely to include options to launch "swarms" of small underwater drones.
US defence giant Northrop Grumman has, in recent years, successfully landed its futuristic X-47A combat drone on the decks of aircraft carriers, regarded as the hardest thing a human fighter pilot has to do.
The Defence white paper also flags Australia's purchasing armed drones to attack ground targets in the style of the US-made Reaper.
Reaper's manufacturer, General Atomics, has recently established an office in Canberra.