Auckland has seldom hosted a more globally important meeting than the nine days of negotiations that start today on the proposed Trans-Pacific Partnership agreement.
The TPP offers the most promising advance of free trade since the failure of the World Trade Organisation's Doha round. Regional free trade treaties are a poor substitute for a global agreement but when they are based on the same principles and open to all countries that can meet their standards, they are the next best thing.
Doha may have failed but it has done the cause of free trade a favour by removing the fear of failure. Previously trade talks of all kinds tended to struggle on, and on, and sometimes cobble together a largely cosmetic agreement because failure was unthinkable. Without constant progress, it was believed, countries would drift back into protective habits.
Doha showed that risk was no longer high. Few countries see much future in closing their markets to foreign competition any more. Even in the recession that followed the global financial crisis the world has not seen tariff barriers rise as they did in the depression of the 1930s.
Trade is these days recognised as a universal benefit even if countries still make heavy weather of bargaining for it.
New Zealand is one of those that has reduced its barriers of its own accord and has done deals with countries of a similar outlook. The TPP is one of them, started by New Zealand, Singapore, Brunei and Chile.
Gradually it has attracted more Pacific rim countries, crucially the United States, and this week Canada and Mexico join the talks.
Inevitably, the presence of the United States threatens to change the nature of the exercise. Strategic considerations are never far from US trade policy and part of the TPP's appeal to Washington may be that it does not yet include China. For the same reason the US might not be too keen to include Japan, where free trade agreements are done for appearances.
But the greatest challenge the US presents to the exercise is in the rules to govern international investment. Agreements on investment have been part of global trade negotiations since the Uruguay round. The TPP may establish a tribunal to which companies can appeal when the government of a country legislates or regulates in a way that alters the conditions that attracted the company's investment.
This is the proposal that antagonises those who will no doubt be protesting outside the negotiations this week. It is said to be undemocratic and an offence to national sovereignty but in truth, trade rules are not that strong. Governments will be able to do what they want. If foreign investors obtain a ruling against them the worst that can happen is that foreign investors will be more wary of that country in future.
It is important that countries signing up to an investment treaty indicate at the outset the sort of health and environmental regulation they will uphold. John Key reaffirmed as recently as last week that New Zealand will not give up its public medical purchasing system, Pharmac, under pressure from US pharmaceutical manufacturers.
Pharmac was not the only possible "deal breaker". Mr Key also said the Government would not sign a TPP that allowed dairy tariffs to remain at present levels. New Zealand, as Trade Minister Tim Groser has also made clear, is aiming for a "gold standard" agreement and has no reason to settle for less.
The TPP's original four signatories set the standard and they should stick to it. If others want to do a weaker deal, they are in the wrong talks. The TPP means business.