'Do not besiege walled cities if it can possibly be avoided," goes the advice from military tactician Sun Tzu - and Prime Minister John Key clearly has that advice uppermost in his mind whenever he is asked to comment on the latest suggestions to pay for Auckland's transport woes.
The most recent came this week in the form of a paper prepared by the group appointed by Auckland Mayor Len Brown to consider how to fund Auckland's $12 billion future transport shortfall.
That set out an appetising menu for Aucklanders, who were asked to choose between rates and fuel tax hikes mixed with tolls on new roads, or tolls and congestion charges, a la inner London, also sauteed with rates and fuel tax rises.
So began the second screening of Groundhog Day, in which Brown pops up with a bright idea and the PM knocks it back for political, not fiscal reasons.
The same scenario played out in February last year when Brown set out his field of dreams vision, complete with a rail loop to rival the Hogwarts Express. There was rapture. Until somebody spotted the fine print of what it would cost. Never fear, Brown also had the solution for the fine print - a special, elite, gold star tax rate just for Aucklanders. There were numerous options to choose from.
It could either be an addition to income tax, or extra GST for Aucklanders. There could be regional fuel taxes so Aucklanders paid more than the country mice. To ensure Aucklanders didn't feel too isolated, another proposal was a levy on visitors to the City of Sails to help in Brown's quest to make it the City of Rails.
Thus, it was early on in his reign that Brown went some way to putting meat on Bill English's 2009 advice to Aucklanders if they wanted to avoid big-spenders, "Don't elect a mayor who is nuts."
New Zealanders have an affection for nutty mayors, but what Brown didn't take into account was that Aucklanders do not have a similar affection for taxes, even if they are cunningly disguised.
John Key certainly took that into account. Back in 2012, he tried to be diplomatic, saying Brown's interesting solution would "focus minds on what is on offer". He mumbled English's fiscal rectitude phrase du jour about the danger of splashing money round on "nice-to-haves". He suggested there would be "a range of views" on whether Aucklanders wanted to pay those extra taxes. What Key meant was there would be two views - one held by Brown that Aucklanders were stampeding down Queen St towards the mayoral chambers, wallets rattling, in their eagerness to pay, and the other held by 1,508,943 Aucklanders who most vehemently did not want to.
Brown got more cunning as the year passed and tried to ensure the latest proposals were harder to dismiss, mostly because of who put them forward. The group suggesting them spanned businesses, unions and transport campaigners, including the champion of the motorcar, the Automobile Association.
Yet it came to pass that when confronted by the proposals for what effectively amounts to extra taxes for Aucklanders, albeit phrased differently, Key remained wary. He pretended not to rule out any of the options while effectively ruling them out.
We don't have the gantries or technology, he said when asked about congestion charges. And when asked about tolls on existing roads, he announced, "It's one thing to have a toll, another to have a toll without any alternative, and a third thing to have a toll on a [road] you've already paid for."
The issue was Aucklanders, and Aucklanders were voters: "Can Aucklanders afford to pay for that, and would that be fair?" So he gave his own preferred option - to carry on as things were, raising money from national fuel taxes.
Both in 2012 and this week, those reading Key's lips rather than listening to his words distinctly saw him mouth a big, fat "not on your nelly". Because Key knows that should he allow Aucklanders to be hit with their own special taxes, it will be the politicians who let it happen who become the nice-to-haves.
As for English's advice on how to choose a mayor, it remains to be seen whether Aucklanders will have a wider variety in the nuts pick-and-mix bowl in 2014. The early signs are ominous. As well as Brown and John Minto, Maurice Williamson is weighing it up. Given their history, it is possible English would put Williamson in that category.
But at least the trend of coming up with unique ideas to fund Auckland's transport could continue. He's a fan of tolls and if he can't get that through, just give him a $50 note and a 3D printer and Thunderbirds are go - all the way down the Pakuranga Highway.