The trouble with relying on US, UK or Aussies to fight any enemy the NZ might encounter when discussing what you need is that these scenarios envisage an isolated incident where NZ by herself is the victim of an invasion, a very unlightly scenario indeed.
As far as I can see, the most likely risk of an invasion of NZ is as a secondary development following a major realignement of the world as we know it, something that is not as unlikely as one may think.
Imagine a situation where the Iranians finally manage to put together a viable nuke and a long range delivery system and, in accordance with the present leaderships declared goal actually launch against Israel.
Even if only one or two nukes hit Israel, the resulting carnage would swamp Israely disaster releif capabilities and significally reduce defence forces military ability as parts of the military and political command structure would be taken out while large parts of the military rescources would be busy handling the many effects of the nukes.
Imagine then that the Palestinians and Syrians see fit to take advantage of this unprecedented low in Israely defence capability and decide to liberate the occupied areas, igniting a widespread rekindlement of muslem holy war
fanatics throughout the muslem world, parried with some sekular, arab countries grabbing the possibility of vindicating their previous military losses against Israel and at the same time gaining popularity with the often fairly large zealous religious elements of their population, plunging the entire middel east region into turmoil.
After a very short time the Suez would be closed and oil output from the middle east be seriuosly curtailed.
The US would be fased with the quanondrom of necessary nuclear response to Irans attack, the overriding need to immidiately come to Israels aid as well as the nearly impossible task of shoring up threatened and faltering middle east governments, all at once and all within the time span of merely days.
With the US thus preoccupied the Ukraine and Russia crash in a renewed conflict about gas, which, although not erupting into war, disrupts the gas deliveries to Europe. Togehter with the reduced oil output, this threatens the world with immidiate oil shortages of unprecedented proportions, sparking civil unrest in many third tier nations as rich european countries buy up all availiable oil on the market.
EU's leadership react strongly to what they perceive as a poorly veiled blackmail to make the EU pay for the gas delivieries that the Ukraine cannot pay. Russia on her side, react with alacricity to what they on their side see as unfair accusations from the EU and tensions rise. Russia deploys some military forces to preassure Ukraine, a move that sets off visceral reactions in Polands population and government, resulting in a full scale mobalisation in a country already experiencing major gas and oil shortages due to its low strategic oil reserves at the outbreak of the crisis.
In this volatile situation the Russians, through a fluke of fate resume Bear Delta flights all along the Norwegian coast for the first time since the cold war. Although this was planned a long time ago the Norwegians and Brits are not convinced that this move, overflying the oil installations of the North Sea, rescources that are just barely feeding Europe with the bare necessaties of oil, has nothing to do with the present tension. The fact that the Bear D recon planes are more or less indestinguisable from the similar long range bombers does not exactly alleviate European worries.
Following intense requests from the European governements the US redirect one of the three carrier battle groups on route to the Mediteranian to rptoect the installations in the north sea, a move perceived as profoundly threatening by the russians.
The escalating tensions in Europe, the nuclear disaster and ongoing war in Israel, threatening Israels very existence, Irans unprovoked nuclear attack, the continuing free for all in the middle east as well as the impending world wide all threaten to undermine US influence world wide.
A resurgence in world wide terrorism by relegious zealots is inspired by the muslem incursions in the middle east, resulting in, amongst other things, a chemical attack on Disney world, killing nearly 1000 children, a new, allegedly Iranian inspired terrorist organisation, tips the scales in the White House situation room and the US succumbs to popular preassure, launching a major nuclear attack on Iran.
This attack is met by outrage over most of the world, sparking further civil unrest, and international relations deteriorate significantly.
Russia percieves the US nuke attack on Iran as proof that the US is out of control and mobilizes. A totally unnecassary incident on the russian- polish border results in fighting, that is only contained by a diligent negotiation campaign by the Finnish president.
Feeling that the US by its attack on Iran has lost its moral superiority, China decides to finally unify with Taiwan, a move Taiwanese authorities and people strongly oppose, resulting in all out war between the parties, a war that is not won as easily as the Chinese Peoples army thought, thus the brutal fighting contiunuing and the US honoring their previous guaranties for Taiwans safety.
By this time the US military is overwhelmed by the multi tiered crisis with battle groups engaged or on their way to the Med, the North Sea and Taiwan. The EU are more than busy bolstering their borders to the east as well as protecting their last remaining oil reserves and the Australians already deploying forces in aid of the US.
In this situation an unholy alliance of Somalian rebel forces, Golden Triangle drug lords and surreptious involvement by the Burmese military decide they would like to relocate to New Zealand.
Equipped with two large container ships, remodelled to accomodate Frogfoot VSTOL fighters hidden under tarpulines as well as a RoRo ship with vehicles and on board fast patrol boats their 3000 strong rebel outfit head out towards New Zealand.
Would you like something to shoot with?
