Diplomacy is always a tightrope but what happens when your old mates turn on your new friends and demand you line up with them?

Today, The Detail looks at the stoush over "the club" – the Five Eyes security agreement - that's turned ugly, and whether it threatens New Zealand's independence and relationship with China. 

Tension between Five Eyes and China has ramped up over the crackdown on Hong Kong. Last month, the intelligence alliance issued a joint statement criticising Beijing's imposition of new rules to disqualify elected legislators in Hong Kong.

China responded with the warning: "They should be careful or their eyes will be plucked out."

New Zealand has also got involved with the row between China and Australia over the doctored image of an Australian soldier holding a knife to the throat of an Afghani child.

Robert Ayson, Professor of Strategic Studies at Victoria University, tells Sharon Brettkelly "quiet diplomacy is over but at the same time every time there's an opportunity to bash China do we really want to be part of it?"

Ayson explains the history of Five Eyes and how the "world is ripe for intelligence playing a broader role".

Five Eyes is an intelligence alliance with "common adversaries, common threats, common risks" whose origins go back to World War Two and led to an agreement between the US and Britain to exchange information on signals intelligence. By 1956 Canada, Australia and New Zealand had joined.

Ayson says there are three rings to Five Eyes, the first is the intelligence sharing, the second is the growth of wider policy areas such as Customs, police and law enforcement. New Zealand Five Eyes ministers regularly attend a meeting of the alliance members with topics ranging from cyber security to co-operation against people smuggling.

The third ring, he says, is the way Five Eyes is being used as a diplomatic community.

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"Because Five Eyes symbolises and connects us back to that original commitment to intelligence co-operation, to thinking about common adversaries, it's easy to see why countries on the other end of Five Eyes statements are going to take some umbrage from time to time."

Ayson describes a level of trust between the Five Eyes members that each of the participants believes the other four will "safeguard the material that they exchange and that's a very intimate and close relationship going back decades.

"That type of relationship and trust is quite rare in international politics and it's one of the reasons the Five Eyes, the intelligence dimension in particular, remains really quite unique and quite special."

But he says because Five Eyes symbolises and connects us back to a commitment where we are thinking about common adversaries, it's easy to see why other countries might take umbrage from time to time.

And - "increasingly we are seeing (us being) drawn into this contest between the United States and China."

"Probably not enough of us in the broader debates have taken this up and said 'do we really want to do this?' I think it's a quiet, step by step evolution."