Australia is planning to acquire a remarkable variety of strike missiles—weapons designed to hit distant surface targets. They will differ in capabilities and will variously be carried by aircraft, ships and trucks.

Despite the differences, great capability overlaps exist among the eight planned missile types and versions.

Strike missiles are key contributors to the strategy of deterrence by denial required by the defence strategic review, the public version of which was published in April. Facing such missiles, a hostile power is supposed to hesitate before placing surface warships, ground forces or bases close to Australia.

Most of the planned strike weapons will be cruise missiles. That is, they will fly like aeroplanes and rely on small size, low altitude and perhaps stealthy design to penetrate defences. But three types in Australia’s plans are ballistic: they will fly like balls, thrown to the upper atmosphere or beyond by their motors to descend on targets at a great speed that will make them hard to intercept.

Cruise missiles used to always be divided into anti-ship and land-attack weapons, but the categories are merging. We increasingly see weapons that perform both functions and are lumped together as ‘strike missiles’.

Strike missiles are expensive. Most cost at least US$1 million at the factory gate, then more to be made operational and maintained in stock.

Bombs cost only tens of thousands of US dollars each, but attacking with them will be impossible if a target is too strongly defended or too far away. That’s when strike missiles are necessary.

The issue of cost raises the question of inventory sufficiency. It’s unlikely that any country at war will think it has nearly enough strike missiles in stock.

What follows are descriptions of Australia’s planned strike missiles—first the air force’s, then the navy’s and finally the army’s. Acquisition timing is often unclear.

Lockheed Martin AGM-158B JASSM-ER—A standard US air-launched cruise missile primarily intended to hit land targets.

Canberra last year announced acquisition of AGM-158Bs, initially for the Boeing F/A-18F Super Hornets and later the Lockheed Martin F-35A Lightnings.

The weapon has a stealthy shape, helping it to get past radars, fighters and surface-to-air systems.

In principle, it should become usable against ships when fitted with a planned datalink, through which it could be redirected as targets changed course. Its infrared seeker should work against maritime targets.

F-35s will lose stealth and range when carrying AGM-158Bs, because the weapons won’t fit in weapon bays. But the missiles will be able to fly far.

Standard range is almost 1,000 kilometres, to which can be added the radius of the fighter, which can easily exceed 1,000 kilometres with in-flight refuelling. Announcing its approval in 2022 for the possible sale of 80 JASSM-ERs to Canberra, the US State Department ambiguously suggested that Australia’s version could be the AGM-158B-2, which will fly much further than 1,000 kilometres.

Australia has operated an earlier, shorter-range AGM-158 version, the AGM-158A JASSM, on F/A-18A/B Hornets. The aircraft are now retired, and a Department of Defence spokesperson confirms that the weapon is not now operational with the Royal Australian Air Force. But a source who is familiar with the inventory says Australia has retained its AGM-158A stock. Since the AGM-158A has some compatibility with the Super Hornet, the RAAF may have an option of eventually returning the weapon to operation.

Lockheed Martin AGM-158C LRASM—Essentially an AGM-158 version with a datalink and a more complex seeker that also homes in on radar signals and is therefore better at hitting ships.

The AGM-158C can also be used against ground targets, but it is unnecessarily complex for that purpose, for which the AGM-158B should be preferred.

Australia has been planning to equip at least its Super Hornets with AGM-158Cs. The defence review called for F-35As also to carry the missiles—again, at the cost of stealthiness and range.

AGM-158Cs will replace the AGM-84 Harpoons, so to some extent the acquisition will update a capability rather than introduce a new one.

Australia’s Boeing P-8A Poseidon maritime aircraft, which probably have a strike radius without refuelling of around 3,000 kilometres, will presumably get AGM-158Cs at some time. If they do, Australia will acquire a bomber-like air-to-ground capability with a very long reach.

The AGM-158C itself may have a range of well over 500 kilometres.

Kongsberg JSM—A Norwegian missile that can fit inside F-35A weapon bays and hit land or sea targets.

Being smaller than the AGM-158B and AGM-158C, the JSM has a shorter range (stated as more than 275 kilometres) and a smaller warhead.

Thanks to its extremely low flight altitude and stealth shaping, the JSM should be able to get very close to a ship before it is detected, so the target would have little time for defending itself. The missile can also throw wild manoeuvres in the last few seconds before impact, confounding attempts to intercept it.

The combination of the F-35A and JSM should present hostile warships with a highly dangerous threat of sudden attack.

The defence review called for JSMs to be acquired for Australian F-35As. The fighters will need updating before they can use the weapons.

Raytheon RGM-109E Tomahawk—A weapon with an unusually long range, mostly launched from ships or submarines and lately updated to hit maritime as well as land targets.

The US State Department in March approved the possible sale to Australia of 220 RGM-109Es in two sub-versions (Blocks IV and V). Japan wants to buy 400. Until now, the US has exported Tomahawks only to Britain.

Despite its range—1,850 kilometres, according to Raytheon, possibly understating it—the weapon is fairly inexpensive at around US$1 million per round, though Australia will pay an estimated total of US$895 million for its batch. That will include equipment and services to make the weapons operational.

Hobart-class destroyers will carry them.

A great limitation is that not enough missile cells are available on the Hobarts even for the ships’ main function, air defence. It seems that few cells can be allocated to Tomahawks.

Another problem is that attacks by ships cannot be frequent, because returning to base for reloading takes days or weeks. On the other hand, a ship may be able to go further from Australia than an aircraft and launch at shorter notice.

Kongsberg NSM—A strike missile of moderate range for launching from ships or trucks against sea and ground targets.

Australia will install NSMs on Hobart-class destroyers and Anzac-class frigates beginning in 2024; the same missile type is also a likely candidate for an army anti-ship requirement. For the navy, NSMs will replace Harpoons, so that acquisition is basically a capability update.

Key advantages over the Harpoon include the NSM’s extremely low flight altitude, use of infrared homing instead of detectable radar, and extreme endgame manoeuvres.

The land-attack function has probably limited value, because of the relatively short range of the weapon, which is given as ‘more than 185 kilometres’. Getting within a few hundred kilometres of a well-defended target could be quite dangerous for a ship.

Raytheon RIM-174 SM-6—An unusually flexible weapon, designed originally to defend ships against aircraft and missiles but itself usable ballistically, mainly against ships.

The SM-6 would be hard to intercept on a ballistic trajectory, but it is an expensive weapon and carries only a small warhead over just a few hundred kilometres. For Australia, SM-6s are really for naval air defence, not strike. Hobart-class destroyers will carry them.

PRSM—The ground-launched weapon that will give the Australian Army a role in the denial strategy. Designed initially for ground targets, it will be upgraded to hit ships, too.

The PRSM (pronounced ‘prism’) flies ballistically. It is intended to go into full-rate production for the US Army in 2025 with a range of 400 kilometres but has been tested to beyond 500 kilometres. That is still very short compared with the reach available from aircraft.

Australia has contributed to PRSM development.

The acquisition cost looks moderate at US$1.5 million per round even for early-production units.

PRSMs will be carried in HIMARS launcher trucks, which when stationary would be hidden. Greatly improving responsiveness, C-130 and C-17 airlifters will be able to swiftly move the trucks around Australia or potentially to the islands of neighbouring countries. Ships could move them forward, too.

PRSM Increment 4—Not actually a PRSM version, but a new missile type with much longer range, still launched from the ground to hit land and, presumably, sea targets.

The weapon is still at an early development stage for the US Army. The defence review implicitly required it for Australia by strongly supporting ongoing co-development and rapid acquisition of the PRSM ‘in all its forms’.

The PRSM Increment 4 will fly further than the initial PRSM by using atmospheric oxygen for the combustion of its fuel instead of carrying an oxidiser mixed with the fuel.

The US Army is looking for a range of 1,000 kilometres from the new weapon.

Editors’ note: This article was amended on 4 and 5 July 2023 to include an update on the status of Australia’s stock of AGM-158A JASSM missiles and the potential for Super Hornets to use them and on July 20 to note that the army may receive NSMs.