Of all the remarkable images emerging from this testing week, the sight of a military flotilla standing off Kaikoura counts among the most extraordinary.

The flags of the vessels included the ensigns of New Zealand, Australia, Canada, and the United States.

The ships were meant to be part of the 75th anniversary celebrations of the Royal New Zealand Navy. Instead the birthday became a rescue effort, with the ships lending assistance to people stuck in the cut-off tourist town of Kaikoura after Monday's 7.8 earthquake.

For protesters objecting to the presence of an American warship in New Zealand waters, the diversion of the USS Sampson from its Hauraki Gulf course to the chilly waters off Kaikoura was a frustrating act beyond anyone's predictions.


But needs must, and the demonstrators were denied the chance to dust off banners and signs used to object to the last visit by a US warship 33 years ago. Given that the US has made the decision to re-engage with New Zealand, other ships can be expected to follow in Sampson's wake.

Opponents of the defence relationship will have opportunities denied them by Sampson's southern mission. They will not have to wait another three decades.

The deployment of the naval vessels for the relief of Kaikoura is in reality an historic event. The only ships capable of rescheduling their mission at short notice were the visiting warships.

The fact they were in domestic waters for the Navy's birthday acknowledges the service which New Zealand has supplied in times of conflict and disaster over the decades.

The willingness of the foreign navies to return the favour reflects the passing of an uncomfortable few years when New Zealand was frozen out of participation in joint naval exercises because Washington disapproved of a law passed by a Labour Government and retained by successive National administrations.

Those with long memories will recall the protests stirred by US warship visits over 30 years ago. Fleets of small boats riding on an anti-nuclear tide took to the water to object to the hulking grey presence of the Navy's Long Beach, Truxton, Pintado, Haddo and Texas, the last ship to stop by here in 1983.

After Labour won power the following year, relations with the US chilled. The welcome mat was withdrawn from the ageing USS Buchanan in 1985 after which New Zealand and the US went their separate ways.

Bilateral military exercises were canned, intelligence sharing restricted and the initials NZ shorn from the Anzus Treaty, the post-World War II security guarantee.

New Zealand has spent the best part of three decades in Washington's military dogbox. Trade and investment however remained unaffected. Starting in the late 1990s, high-level diplomacy resumed.

New Zealand's involvement in Afghanistan and Iraq have helped repair relations and Vice-President Joe Biden's visit in July paved the way for USS Sampson visit.

Under New Zealand law, Prime Minister John Key declared the 9,200 tonne Sampson nuclear-free. Washington has not abandoned its "neither confirm nor deny" policy regarding the presence of nuclear weapons but has adopted a pragmatic view.

In announcing that the destroyer had altered its course for the South Island, Admiral Harry Harris, head of the US Pacific Command, said: "Our prayers go out to our friends in New Zealand as they deal with another devastating earthquake on the South Island. But more than that, our help also goes out."

In times of trouble, that's what friends do. So welcome back America. And thanks for your help this week.