Talk about changing New Zealand's nuclear-free stance couldn't come at a worst time. It's a policy that's time has come and which is now more a national asset than ever

Timing is vital in politics. Sir Geoffrey Palmer knows that from harsh personal experience, having been handed the prime ministership just as the fourth Labour government went into terminal decline. So you've got to wonder why he chose this week of all weeks to pronounce that it would be not only possible, but "desirable" for US naval vessels to return to our ports.

Sir Geoffrey has told Tracy Watkins of the DominionPost that New Zealand could now have US naval vessels back in our ports, and that such a move was "desirable". The key question as to why that would be desirable doesn't get an airing, so I'll try to fill in some blanks here.

Every man, woman and dog has jumped on the bandwagon in the few days since the story ran, and a serious fellow such as Sir Geoffrey is probably feeling deflated by how his words have been interpreted.

The Greens have used it to attack US foreign policy, while none other than the associate minister of defence, Heather Roy, has made it a party political issue by suggesting that the former PM's words somehow endorse ACT party policy to repeal New Zealand's anti-nuclear policy.

Roy rightly says that, "Confusion has been encouraged by many groups around nuclear weapons, nuclear propulsion and nuclear power", and promptly goes onto add to that confusion by talking about repealing the legislation that prevents nuclear-propelled ships from entering our waters and how that law has been "counter-productive" to our relationship with the US.

Our anti-nuclear legislation does ban nuclear armed and propelled vessels, but the Americans could be back in port tomorrow if they were willing to confirm or deny whether a ship was nuclear powered (the US navy doesn't have nukes on its ships anymore, only submarines). So that issue rubs both ways.

We and the Americans spent long years at that impasse, each waiting for the other to blink. But in case no-one's noticed, that's all changed, and how.

What's happened in the interim is, however, is 9/11, and the misconceived wars that followed. Put simply, the US realised it needed its mates, while New Zealand woke up to the fact that, in the Pacific at least, the US remains a firm friend.

Wiser heads have prevailed and the two governments – under multiple administrations – stopped playing chicken, focused on all that they had in common and have reclaimed the used of the word "ally". The US last year agreed that its retaliatory decision to ban New Zealand troops from joint exercises and training is "absurd" and two New Zealand naval vessels have left in the past week for a visit to the US – the first in 25 years.

All of which begs the question, why would we want to change our position now?

The tension created by our anti-nuclear position has gone and we have re-built our relationship with the US regardless. What on earth is to be gained by backing down after we've, effectively, won the argument?

Please don't think this is simply a chance to say 'nah-nah-nah' to the Americans and puff ourselves up for having stared down the world's superpower, although that is a remarkable story and one New Zealand should tell with pride. No, this is both a dumb idea and bad timing because, more than just stopping being a liability for New Zealand, our anti-nuclear stance is now a major foreign policy asset.

Sir Geoffrey was right to say that the world has changed; the world has moved in our direction. As I wrote about here and here, our anti-nuclear stance makes us relevant in a world that is increasingly worried about the "loose nukes" lying around in university labs and behind "rusted padlocks", at risk of being stolen and used for nefarious purposes.

It's as if those commenting in recent days aren't aware that even former hawks such as Henry Kissinger and the man who so strongly harangued David Lange over our nuclear-free legislation, George Shultz, are now supporters of nuclear arms reduction. As Shultz has said:

“As more countries have nuclear weapons, as people worry more about the fissile material that may be lying around that can lead to a nuclear weapon, the less confidence anybody can have that deterrence can be relied on as a way of keeping them from being used,” [Schultz said]. This is because it’s impossible to deter a non-state nuclear actor. Terrorist groups lack the return address upon which deterrence strategy depends...

President Obama's Nuclear Security Summit begins in Washington DC today, one of the largest and most vital gatherings of world leaders for years. Its focus? Those fissile materials. And New Zealand has a seat at the table. Why? Exactly because we're nuclear-free.

Listen to what Secretary of State Hillary Clinton said last year:

"We think New Zealand has a particularly credible voice in the world community on nonproliferation, and there will be a bilateral discussion between our two countries on those issues."

Or what Lt. Gen. Robert Gard of the Centre for Arms Control and Non-Proliferation said on Q+A yesterday:

Your country has been a champion in pointing out the obligation of the nuclear weapon states to take seriously their commitment to pursue negotiations in good faith on effective measures relating to nuclear disarmament. It's well past time that we understood that we've gotta keep our end of the bargain if we want the non-nuclear weapon states to abstain from obtaining the weapon.

In other words, we were first to the top of the anti-nuclear mountain, and it's hardly time to start climbing down just as the world is catching up. No, now is not the time to go changing.