If New Zealand is to become a major regional power on a larger and more prominent scale then it will have to have the political will and guts of one. A good example of taking that first step is to close off its territorial waters to the Japanese Whaling/Research Fleet. If they can prove that they can do that effectivly and (this is key) not give into pressure from the Japanese government which will come. Historically they haven't been able to do that. Another example being a few years ago when the Sea Shepherd vessel Ady Gil (A New Zealand flagged ship) was rammed by the Shonan Maru #2 and NZ did nothing to investigate the collision amongst stern protests from its population, then they "washed their hands" of the captain's fate when he attempted a letigitimate citizen's arrest for the attempted murder and destruction of his vessel. This was the perfect opportunity for NZ to make a statement on an International scale and they basically blew it.
Militarily, the framework for expansion is there, but it all comes down to whether or not they can use whatever they gain in the proper way to become a more prominent regional power.
While I will attempt to keep this as politics free as possible, there are a few things to seriously keep in mind.
Within NZ's region, NZ already is a 'regional power'. The only other countries which can realitically operate in the South Pacific regularly with as much or more power than NZ is Australia and the US. As most defence-minded people do agree, NZ can (and likely should) do more given the gaps or potential gaps in NZDF capabilities, but in terms of increasing NZ's (South Pacific) regional prominence... NZ is already on top.
The next three parts strongly involve
UNCLOS.
As to NZ 'closing off' its territorial waters to the Japanese fleet, those territorial waters consist of the 12 n miles surrounding NZ land masses as recognized under UNCLOS, Part II Sec. 2. In effect, denying the Japanese vessels the ability to dock in an NZ port. While the Japanese vessels might be operating in whale sanctuaries as declared by NZ and/or Oz, unless those sanctuaries are recognized as such under international law or by treaty (like UNCLOS), or the ocean area is internationally recognized as belonging to either of those countries, then the Japanese vessels are operating within international waters and outside of a nation's EEZ. Given that several countries have laid claims to Antarctic territory but at present all such claims are not recognized by international treaty, neither NZ or Australia have legal authority to enforce any restrictions on areas they might claim.
Now, for the claim that the
Shonan Maru 2 rammed the
Ady Gil the official conclusion of the investigation of the incident was "inconclusive"... Having said that, some basic boating knowledge as well as looking at a couple of different videos of the incident, from different angles, then the incident begins to look much more like it was staged/caused by the crew of the
Ady Gil.
While I do not know what the various 'rules of the road' for boating are for all nations, the basic rule in the US is that powered vessels give way to unpowered vessels, and that small vessels give way to large vessels. If one thinks about that, it makes sense that a 24 m, 13 ton vessel with a top speed of ~32 kts could stop, start and turn faster than a larger vessel since the larger vessel would have more inertia to overcome. That strongly suggests that in a collision involving two differently sized vessels under way, the smaller vessel is generally at fault. Highlighting that further, when watching [nomedia="http://www.youtube.com/watch?v=7NuWr_ODXnc"]Ady Gil Collision (view from Shonan Maru #2) - YouTube[/nomedia] of the incident shot from the
Shonan Maru 2, a small wake behind the
Ady Gil can clearly be seen as the
Shonan Maru 2 starts to pass alongside it. That wake is an indicator that the
Ady Gil was in fact underway. Watching the video a little further along, the wake behind the
Ady Gil is clearly increasing in size which is an indicator that the engine throttle has been opened up to accelerate the
Ady Gil and given the position of the
Ady Gil relative to the
Shonan Maru 2, the Sea Shepherd was on a heading to collide with the Japanese vessel when the
Ady Gil increased power and did not turn away to starboard.
Now for the last bit about the captain of the
Ady Gil, Pete Bethune boarding a Japanese vessel to make a "citizen's arrest"... I freely admit I am not a scholar of NZ law, so it may well be possible and legal under NZ law to make a "citizen's arrest". However, unless the attempt was made while within the 12 n mile territorial water limit around NZ, or aboard a NZ-flagged vessel in international waters, then it does not matter whether NZ law has a provision for making a "citizen's arrest". In this case, Pete Bethune boarded a Japanese-flagged vessel in international waters without permission which means that Japanese and/or international law is applicable, not NZ law. If things get uglier between groups like Sea Shepherd and the ICR, future boarding attempts might well find themselves confronted by armed security teams like those now serving on merchant shipping in the Red Sea and Indian Ocean.
-Cheers