READ MORE: Spying on Kiwis may save lives
This will likely emerge as the pivotal question in the coming debate. If Kiwis are to sacrifice legal protections from surveillance, then what is it we are getting in return?
"New Zealand does face a range of threats", says the review team of Sir Michael Cullen and lawyer Dame Patsy Reddy, but they won't tell you what they are.
They did add: "We also strongly encourage the agencies to be more open with the public about the nature of security risks, as overseas intelligence and security agencies are increasingly doing."
This suggests it is possible to know more.
The review suggests a merging of the two laws that govern the Security Intelligence Service and the Government Communications Security Bureau.
It is a contrast to the benefit and reasoning of the historical separation. In doing so, it would remove the law that bars the GCSB from spying on Kiwis.
It is this change that appears the greatest. For years, that one line in the law was recognition the power of the electronic intelligence agency as a tool of the state was so great it needed a legislative wall to protect the interests of New Zealanders.
In terms of intrusiveness, the power of the GCSB has never been greater and will, beyond doubt, increase in line with technology.
So what great danger exists which has shifted the balance?
The reviewers point to globalisation, greater online communication and the rise of ISIS but there are no specifics.
There is a reference to "New Zealanders onshore (who) have expressed intentions to conduct domestic attacks".
Australia also had this - remember the teenager who planned on catching a kangaroo, stuffing its pouch with explosives and letting it loose in Sydney?
This is not the systemic campaign of violence by the IRA which turned the United Kingdom into a nation willing to sacrifice so much freedom for security.
Instead, the review offered hypotheticals - that cancelling the passport of those travelling abroad to fight with terror groups might cause someone to "react violently or turn their attention to domestic attack planning".
It adds: "The NZSIS believes that unsophisticated attacks or spontaneous acts of violence, as have occurred in other Western countries, remain a possibility."
None of this is concrete, and if anything seems to suggest a "lone wolf"-style attack which intelligence agencies are broadly unsuited to stop.
It points to 40 people on the "watch list". There are always 40 people on the "watch list", no matter the level of risk. It represents the SIS level of capability, not the level of risk.
If there is increased risk it has not been revealed by the reviewers. Nor has it been revealed by the agencies or the ministers in charge of the agencies.
There have been no cases (or at least any made public) in the courts that illustrate the threat to New Zealand.
The reviewers make a compelling case for streamlining intelligence analysis and action. Efforts to have the SIS and GCSB cooperate have been frustrated by a lack of a clear united purpose.
The move in recent years to house the agencies together did not remove historical barriers.
It has been clumsy, internally, and has not allowed the various agencies to use their experience and skills to the greatest benefit of New Zealand.
There is merit, as the review says, in having legislation which sets out clearly what the agencies can and cannot do legally - but mostly in creating a shared purpose and vision.
That doesn't necessarily require an extension of the agencies' legal powers.
The main underlying benefit of the review is it tells the public more about these secret agencies. This has been the case with a number of official documents released on the function and work of the agencies since the 2012 illegal spying on Kim Dotcom and the leaks by whistleblower Edward Snowden.
There is an increased culture of accountability and openness. It is an environment in which New Zealanders are more able to make informed choices about that which the government does in its name.
The greater openness has yet to extend to the threats faced - the dangers which require us to exchange of freedom for greater security.