Heading his wish list for the 2020s are at least 100 F-35 Joint Strike Fighters and 12 Growlers - the electronic warfare equipped version of the F/A-18 Super Hornet.

The former fighter pilot told guests at an Australian Strategic Policy Institute dinner on Tuesday night the alternative was to be like New Zealand.

``We're a pretty wealthy country, we're actually one of the wealthiest countries in the world - we've just got to make a decision whether we want to control our environment to a certain respect,'' he said.

``Our other choice is to go down the New Zealand route - it's pretty simple.''

The Air Marshal indicated New Zealand had given up on funding its own defence and hoped that in the event of a crisis its friends would come to the rescue.

He said Australia needed the JSF because by the mid-2020s the Super Hornet just wouldn't cut it against the planes our neighbours are considering buying.

And, if we stick with the stealth fighter, quantity has a quality all its own.

``Capacity matters - and anything less than 100 JSFs severely limits the options available to government and only provides a boutique capability,'' Air Marshal Brown said.

``You could buy more Super Hornets (instead of JSFs) but I'd argue (that) by 2025 or somewhere around that it becomes an uncompetitive fighter. You can be the best fighter pilot in the world but if the other guy has got some significant capability advantages over you you just don't fundamentally stand a chance.''

That said, he believes the current combination of a new generation of sophisticated, low-observability, standoff air to surface missiles with the 71 ``classic'' Hornets and the 24 Super Hornets gives Australia a strike capability that would make any potential adversary think twice.

``I'd argue the AGM-158 Joint Air To Surface Standoff Missile (JASSM) equipped (classic) Hornets with the KC-30 (multi-role tanker) is a far superior strike capability than we ever possessed with the F-111,'' he said.

``JASSM achieved its initial operating capability with the classic Hornet in December last year.''

The 4.2 metre long guided missile has a range of almost 400km, carries a 500kg war head and can be retargeted in flight. A subsonic missile, it is slower than the jets that carry it and relies on its low observability to sneak up on the foe.

With a radar cross section said to be about the same size as a golf ball, JASSM lets pilots attack targets well outside the range of ground-based anti-aircraft defences.

Sources indicate each of the missiles - which are fractionally too large to fit into the internal weapons bay of the JSFs expected to be in service with the RAAF by the end of the decade - cost about $700,000 US.

An extended range version that can travel more than 900km after launch has been developed but is not in service with the RAAF.

Despite the government's recent decision to defer the purchase of the next 12 JSFs as part of the Defence cuts in the budget Air Marshal Brown says the fifth generation fighters are still affordable and could be in service with the RAAF before the end of the decade.

``We signed on for the JSF back in 2003 - about 10 years ago,'' he said. ``We decided on a budget, an amount for the joint strike fighter. That hasn't changed. 100 JSFs are still affordable within that original budget range established in 2003.''