As sure as the Tasman Sea tides rise and fall, so too does the rugby relationship its waters reach.
Thursday's bombshell from Rugby Australia chairman Hamish McLennan that Australia could walk away from Super Rugby Pacific may have caught New Zealand off guard, but it is in no way a surprise when you consider the rocky road the two rugby neighbours have ridden since the onset of the pandemic.
First of all, it was New Zealand Rugby who decided to blow up Super Rugby completely. While that had looked increasingly inevitable given South African dalliances with a move north - in some ways NZR's decision gave SARU the out they needed - it still didn't go down without a fair dose of anger.
Next came NZR's position that they would invite only "two or three Australian" teams to be part of their new start-up competition. If the decision to blow up Super Rugby had gone down poorly in South Africa, then the cavalier approach to a new pacific-based tournament had RA executives spitting out their chardonnay.
There would be a thawing of tensions when the crossover Trans-Tasman series was created for 2021 and an agreement that Australia would indeed have its five teams included in the new pacific competition planned for 2022, but again the relationship would sail into troubled waters.
The decision to withdraw from the third Bledisloe Cup game in Perth last year was seen as the ultimate insult by Rugby Australia. Having already moved the game once as part of the difficulties associated with staging international rugby amid the pandemic, RA had already made concessions to get the game played - including staging the first two Tests at Eden Park.
So when the All Blacks refused to jump on the plane to fly to Perth - their reason being that there was not the requisite certainty in the Rugby Championship draw which was to follow - a trans-Tasman rugby civil war was very nearly the result.
Both sides accused the other of misdirection, while RA chief executive Andy Marinos later accused NZR of never having the "intention to play Bledisloe III".
A week later the game was played, followed by a successful Rugby Championship, paving the way for the announcement of Super Rugby Pacific and the belief that the two rugby nations were now charting the same harmonious course.
That continued when the Super Rugby Pacific draw had to be rearranged and frontloaded with local derbies as the omicron COVID variant arrived, before a successful - if poorly attended - Super Round heralded the unification of the fledgling tournament for the first time.
What followed over the next six weeks was a competitive string of cross-country matches that saw Australian teams secure a collective seven wins over New Zealand - up from two in the 2021 Trans-Tasman series - and lose a few more by just a matter of points.
It also heralded an historic moment for Super Rugby, with the Drua playing their first two matches on home soil in Fiji. Their narrow losses to the Highlanders and Chiefs in Suva and Lautoka provided some of the scenes, and moments, of the tournament.
And then, last Saturday, the Brumbies went within one point of reaching the final - and it is indisputable that Dan McKellar's side should have had a late penalty kick to defeat the Blues.
Perhaps that failed decision from New Zealand ref Ben O'Keeffe was the final straw for McLennan?
Whatever the case, the RA chairman knew exactly what he was doing when he suggested there were no guarantees from RA beyond next year, upsetting what will have been an overwhelmingly positive narrative for Super Rugby Pacific across the ditch.
"We'll honour our commitments in '23 but we need to see what's best for rugby in Australia leading up to the RWC in Australia in '27," McLennan told foxsports.com.au
"All bets are off from '24 onwards with NZ."
Just 48 hours out from the Blues-Crusaders final, this was a perfectly timed verbal from McLennan with no other aim than to garner a reaction.
And that it did, with NZR boss Mark Robinson taking a swipe of his own in a response to the Sydney Morning Herald: "From our view, NZR is committed to our relationship with RA and any discussions in relation to the future of Super Rugby will be had first and foremost with them, and not through the media."
Like all the great competition carve-ups, where television deals and broadcast ratings govern all, this is largely about who gets what. And unlike the SANZAAR coordinated deals of the past, there is no revenue sharing agreement between NZR and RA - each governing body has their respective deals with Sky and Stan Sport and what they brokered is what they get.
At $[AU]89m and $[AU]33m, the figures are a Tasman Sea apart.
Meanwhile in the background NZR has done its deal with private equity firm Silver Lake, and Australia has gone and secured the 2027 and 2029 Rugby World Cups to follow the 2025 British & Irish Lions Tour.
RA, too, has private equity suitors in both Silver Lake and CVC, its positioned strengthened since the World Cup announcements were made.
And that is largely the difference between now and the early days of the pandemic when the Australian game was on its knees. Back then, RA had little bargaining power with New Zealand, but now with its house in order, both on and off the field, it is in considerably stronger position.
And NZR won't want to isolate itself further from the rest of the rugby world.
Hopefully, for both sides, it won't come to that. While domestic competitions sustained themselves during the pandemic -- and saw more than 40,000 flock to Suncorp Stadium for the Super Rugby AU decider -- the repetition of matches was starting to wear thin.
And when it comes to the most important rugby team in the country, the Wallabies, from which so much of the revenue that supports the game is driven, coach Dave Rennie knows exactly what he wants.
Having taken the Chiefs to two Super titles earlier in the year, Rennie knows a trans-Tasman competition benefits both sides, too.
"I think it's important that we play the Kiwis and I reckon a lot of people think that we need to play the Kiwis, [but] they don't need to play us because they can play each other," Rennie said of Super Rugby Trans-Tasman last year. "But New Zealand sides are very similar, they play a high-speed, high-skill game and they defend similarly, they attack similarly."
So while Rugby Australia might think it doesn't need New Zealand off the field, the desires of the Wallabies coach would suggest otherwise.
And while NZR may have had the right to look down its nose at Australia from an on-field perspective, the past seven weeks have shown that their neighbours are a different opposition to even 12 months ago.
There is also the thinking that the two nations need to be united at the World Rugby level, so that issues such as the 20-minute red card replacement are at least entertained before they are dismissed by the strong northern hemisphere block.
Could McLennan's comments derail the rocky relationship once and for all? It's possible, but it won't be a surprise to see tensions thaw once again and a more equitable arrangement in terms of broadcast revenue carved up so that Super Rugby Pacific is kept alive.
And there was so much that was good in the past six months that it would be sad to see Super Rugby Pacific crumble completely after just two years.