Transtasman tension rose again this week over deportations - but a briefing recently sent to ministers makes clear: "Australia matters more to New Zealand than the reverse."
The deportation issue flared again after an Australian television reporter was given extraordinary access to taunt 501 deportees as they boarded a chartered flight to New Zealand, a process Australian Home Affairs Minister Peter Dutton said was "taking the trash out".
Australian Prime Minister Scott Morrison also increased pressure for a two-way transtasman travel bubble, saying the hold-up was all on the New Zealand side.
Both the travel bubble and deportation issue were touched on in a revealing Ministry of Foreign Affairs and Trade (Mfat) briefing, delivered last November and sent to the Foreign Affairs Minister, and on to the Prime Minister and key ministers including for finance, trade, and Covid-19 response.
However, the main message was the vital importance of the relationship, in a world made more volatile by the pandemic and its massive health and economic fall-out.
"Covid-19 has consequences for our foreign and trade policy as serious as the Great Depression and is exacerbating existing geostrategic challenges," warned the briefing, obtained under the Official Information Act.
"Global governance is becoming more contested; US/China competition is intensifying and reducing others' room to manoeuvre; countries are retreating behind their own borders; and security threats around the world are increasing.
"Going forward, we expect to be operating in a world that is less open, less prosperous, less secure and less free. It will be harder for New Zealand to pursue our interests and we will want to work even more closely with Australia and other key partners."
The briefing stressed the fact that the transtasman relationship "lies at the heart of New Zealand's prosperity and security", including on new challenges like equitable vaccine distribution and Covid-19's impact in the Pacific region, and recommended ministers talk to their Australian counterparts "at the earliest opportunity".
Restoring free travel between the countries as soon as safe to do so was in New Zealand's interests, officials advised, and would "heighten the closeness of our bond".
This week, the Australian Prime Minister said his country was ready for the bubble: "If the New Zealand Government doesn't wish Australians to visit New Zealand and spend money in Queenstown or Wellington, or other parts of a country, that's a matter for them, it has always been a matter for them".
The delay in implementation has become an attack line for opposition parties here. National leader Judith Collins this week said the tourism sector was desperate for two-way travel, which could be done if people show a negative pre-departure test within 72 hours of travelling.
Collins also called for New Zealand to retaliate against the deportation policy by sending Australian criminals back.
Prime Minister Jacinda Ardern has declined to be drawn into a "tit for tat", but her ministers have been less restrained - Foreign Affairs Minister Nanaia Mahuta said Dutton's comments "only serve to trash his own reputation".
Another source of recent tension has been the imminent deportation from Turkey of an Isis-linked 26-year-old woman and her young children. Suhayra Aden left New Zealand aged 6 and grew up in Australia, but New Zealand is apparently the only option for deportation because Australia cancelled her citizenship.
The November 12 Mfat briefing, which preceded those controversies, noted "an essentially positive environment" did have irritants, including "Australia's turn to more hard-line immigration policies over the past 20 years".
"Australia's deportation policy in particular remains corrosive to the bilateral relationship and vexing to the New Zealand public.
"A large proportion of New Zealanders in Australia have little or no access to the entitlements and opportunities of Australian permanent residency and citizenship, and vigilance is required to ensure their rights are not eroded further."
The briefing outlined how New Zealand benefits Australia - providing a stable and predictable ally and likeminded actor on the global stage, and, because of the single economic market status, adding "more than another 'Western Australia' to the Australian economy".
The roughly 700,000 Kiwis living in Australia are more likely to be in fulltime employment and pay more taxes per person than others in the community, the document stated.
"But we remain realistic about the asymmetry in our relationship. The long-standing assessment is that Australia matters more to New Zealand than the reverse."