The recent announcement of Rocket Labs Atea Rocket development raises the possibility that New Zealand could, if it wanted to, develop a medium range ballistic missile. Such a missile would be similar to the AGNI-II developed by India.
Such a missile would have to be 50%-100% bigger than the Atea to be useful with a range of about 2,000 miles.
But where most nations immediate thought for arming a ballistic missile would be a nuclear warhead New Zealand might have more restrained uses. Two that spring to mind are:
1. Research and observation
2. Delivering torpedos.
The typical 324mm torpedo weighs about 200kg and is about 3m long. Delivered to within 5km of the target zone, re-entering by parachute like the old ASROC, it could then home in on a target submarine or ship. At night it would be practically invisible sudden disaster.
If your ambition is to be able to sink shipping anywhere within New Zealand's EEZ ten minutes after pushing the launch button then such a delivery system sounds like a far cheaper way of doing so than sending a frigate, and so much quicker and less messy (in terms of who saw what when) too.
If, that is indeed, our objective.