In many ways it comes down to trust. Trust in a leader and an institution. Trust, even, in human nature.

As of this week New Zealand has routinely armed police officers patrolling our streets. It’s just a six-month trial and is just in three police districts – Counties-Manukau, Waikato and Canterbury. Still, it feels like a significant social step for New Zealand made with relatively little fanfare or public consultation and Police Minister Stuart Nash shrugging off the crossing of this Rubicon as merely an ‘operational decision’. Despite a well-covered announcement a few weeks ago, the first day on Monday passed with little media attention.

The move raises fundamental questions about the relationship between our police force and citizens, about the risk of ‘creep’ from these first few regions, and of whether you feel more or less safe for having armed police on the streets.

It brings to mind, for me, the Dirty Harry movie and Clint Eastwood standing there with his Magnum 44, except instead of asking if we feel lucky, the question is one of trust. You've got to ask yourself one question: 'Do you feel like you can trust them?' Well do ya, punk?’

The new policy announced by Police Commissioner Mike Bush just three weeks ago meant “a trial of Armed Response Teams (ARTs) to support Police’s tactical capabilities on the frontline to minimise the risk of harm to the New Zealand public and our staff”.

On one level, the change is an incremental one. The ARTs are made up of members of the Armed Offenders’ Squad. The AOS, in turn, is made up of specially trained police officers who, when they’re not called up to AOS duties in an emergency, are everyday officers doing everyday policing. Now, however, we have these three teams on “on duty at peak demand times, seven days a week”. They “will be routinely armed, equipped, mobile and ready to support our frontline with any events or incidents that require enhanced tactical capabilities.”

It’s the fact that they are “routinely armed” that stands out, because both the commissioner and minister have been assuring us for some time that wouldn’t happen.

On March 4, 11 days before the Christchurch mosque shootings, Bush went on Newstalk ZB to explain that while police were armed that weekend as they hunted an armed man in Canterbury, there was no intention to “routinely” arm police.

“I do want to reassure everyone that there is no intent for the New Zealand Police to have routine arming," he said, before adding, it would be a "big decision that you can never come back from… That's not the way we police in New Zealand”.

He wrote in a Facebook post/blog that day that, “routine arming would fundamentally change our relationship with the New Zealand public, and it would have a significant impact on the trust and confidence which we have worked hard to build”.

Hey, that was before March 15, you might say. But even after, in May, Bush told Q+A he did not see routinely armed police as inevitable.

“Quite firmly, I do not. I hope we never go there.”

He went further, saying the existing policy needed no changing, no siree.

"We've got it absolutely right".

Then in October, Bush was asked again by Stuff, on the back of news that a New Zealand Police Association poll had seen public support for an armed police force climbing from 55 percent to 61 percent, the highest in their six surveys back to 2008.

Bush said he had considered the country’s operational environment.

"As part of this, I have of course considered whether routine arming would be appropriate, and I can confirm that NZ Police has no plans to become a routinely armed police service.”

You could hardly get firmer denials. And let’s just check this out again… on October 15 Bush said he had considered the operational environment and no routine arming of the police. Yet just three days later - three days! - he is quoted in a police statement thus:

“Following the events of March 15 in Christchurch, our operating environment has changed.”

Again, the statement says: “Our AOS is normally on call 24/7, but for the trial they will be routinely armed, equipped, mobile and ready to support our frontline…”.

That is as big a flip-flop as you can imagine. Which raises questions about how much we can trust Bush, even after he had said earlier in the year how important trust is between enforcement and citizens. He hoped we’d never get here. He thought we had is absolutely right. So when and how did he change his mind? Can we really believe he changed his mind in the three days between October 15 and 18? No.

So was he just lying? Or is his argument that a trial in just three centres - three of our largest centres with a combined population of over 1.5 million, or more than 30 percent of all New Zealanders - doesn’t count? Because routinely arming police in regions covering about a third of the country’s people sure counts to me.

Bush’s arguments in favour (and there may be more and better ones) include the rise of meth and his desire to keep people safe. But which people?

The arguments against include the risk of an arms race as criminals see the news and respond, the fact Maori and Pasifika are eight times more likely to be at the receiving end of “police violence” and the fact the number of assaults on police with a firearm and small and falling. Regarding Maori and Pacific people, I’d note that Bush to his credit is the first commissioner to admit to “unconscious bias” amongst police officers. But add guns to that bias, and it raises some interesting questions.

It’s also interesting to wonder about human nature and the discipline required to not use the tools you are given.

It all feels like we’ve leapt to a mammoth decision without proper consideration and debate. It feels not like a societal tipping point or a building, inevitable consensus, but the pronouncement of a single commissioner who had spent months assuring us he had no such intention of doing what he’s just done.

Most of all, when you contrast what the police - and Bush in particular - have said and what they’ve now done, I’m left thinking of Dirty Harry. I’m left thinking whether, after all the denials have been so quickly ignored, we can trust the leadership of the police with this momentous decision. And if we can trust them not take the next step, or the next one, without more consultation and debate.

We should all be watching very carefully indeed over the next six months and demanding a lot more say in the decision that comes at the end of this trail than we got in this one.