You mis-understand me I think. The Surface Ships (and indeed the Maritime Patrol & Transport aircraft) still have a role and still represent a useful return on a limited budget. Moreover, they still have a practical role in peacetime. Fighters on the other hand are essentially one-show ponies. It's about return on investment against a limited budget and balancing of other priorities.
A defence force has one role and that is to prepare to defend the country. Anything else is secondary. WRT to fast jets, in peace time they like surface combat vessels are deterrents, telling any potential adversary that we will make an military action against us expensive, so they still are VfM (Value for Money), just like an insurance policy.
@ngatimozart How many Harpoon missiles could one launch from the back of a C-130J’s ramp? That would be a much cheaper way of acquiring maritime strike capability over a much larger area… to complement the P-8s on order (which would be needed to provide targeting).
Nobody does it because a C-130J wouldn't survive in contested airspace. It wouldn't get close enough to launch the Harpoons before it was shot out of the sky. Against a modern day naval air defence system it is doubtful whether or not the Harpoon will make it past the defences to reach its target anyway. It's an obsolete weapon now. You have to have the correct capabilities for the mission sets otherwise you are wasting both money and more importantly lives.
If you read my post
above it shows our AOMI and explains why such a capability is required. The Pacific War of WW2 is a good reason why. The IJN was very close to closing the SLOC between the US and Australia / New Zealand. If they had achieved that the whole war may have taken a different hue for a longer period.
Let's move on from scenarios based upon the world of 80yrs ago - hell,
Australia and Japan just signed a Defence Agreement
If the CCP decides to extend any war outside of the First Island Chain and beyond the Second Island Chain then we would be in serious trouble. We are also obliged to go to Australia's aid in any attack upon Australia, so since Australia is adjacent to the Second Island Chain they will most likely be attacked by PLA forces, most likely PLA-RF, PLAAF, PLAN & PLANAF forces. Our 900nm moat hasn't protected us from enemy attacks for 108 years.
If such a scenario came off, the small contribution made by a New Zealand air contribution of fighters/strike aircraft (maybe 1 - 2 SQN worth) would be negligible. It would also represent a poor return on investment. Don't get me wrong, I have very high regard for the New Zealand Military but I think their Govt made the correct one in the late 1990s/early 2000s when they cancelled the F-16 deal and disbanded the RNZAF air combat force. If it ever got to the situation where New Zealand was being threatened directly with Military action it means the enemy had presumably already beaten Australian, US and other Allied forces. 1 - 2 SQNs of RNZAF fighters is not going to make a difference here.
It depends upon the platform acquired and how it is used. If I was in charge of NZDF capability and acquisitions approvals (which I am not), I would look at the F-15EX because of its range and weapons carriage capability. Two squadrons of those (36 aircraft) would be enough. Having a flight or two of RNZAF F-15EX working with a section of two RAAF F-35A creates a dangerous combination. The USAF are looking at a similar combination with their F-15EX / F-35A; the F-35A to open the door and the F-15EX to wreck the joint, be it a surface or airborne target. The RNZAF and RAAF have worked together since the days of WW2 in the Pacific with RAAF Boomerang fighters marking Japanese targets for RNZAF P-40 Kittyhawks to wreck, which they did with great success.
WRT to your comment about one or two Sqns not going to make a difference, you are wrong because they will. Today it's about how you use the aircraft and the ability to use / transfer information to / from it. So it has to have a TDLS (Tactical Data Link System) such as Link 16, and some computing capability within the aircraft. This is a force multiplier and the F-35A can provide the targeting data over a TDLS in real time with the F-15EX being missile / bomb trucks. The F-15C is able to carry four Harpoon missiles, so if the EX was able to strap on four AGM-158C LRASM that would be great. The LRASM is a far better missile than the Harpoon because it has a larger warhead, longer range, a smart missile, and is a 5th generation LO (Low Observable) missile. The other missile is the JSM (Joint Strike Missile) which is a smaller and lighter missile for use against frigates (<6,000 tonnes displacement) and smaller ships. It too is 5th gen smart missile.
The aircraft I considered were the F-15E, F-16 Block 70 twin seater, and the F-18F. Each has it's pros and cons and the F-15E was deleted because of acquisition and Term Of Life Costs (TOLC). The choice was then between the F-16 and F-18F with both about equal. Then Boeing came out with the F-15EX which they offered for the same cost as the other two and the TOLC had been reduced markedly making it viable. Compared to the F-16 Block 70 twin seater, and the F-18F, if offered greater capabilities for a similar acquisition cost and hence out of the three gave the best VfM or as our American friends say, bang for buck. It also would slot in well with the RAAF and offer them a capability they haven't had since they buried the F-111s.