It puts any reconciliation with Peters into perspective. However, there will be many who will question the settings on Key's moral compass instead. You cannot say you would rather lose power than work with someone and then turn around a couple of years later and offer not so much the olive branch as the welcome mat.
The change in attitude towards New Zealand First is further evidence that Key will do whatever has to be done to secure a third term for National on the Government benches in Parliament.
Even so, Tuesday's wiping clean of NZ First's slate was surprisingly deemed to be something of a surprise by some elements of the political milieu.
The most prominent example was Radio New Zealand's flagship Morning Report which headlined its coverage to that effect.
The "surprise" may have simply reflected genuine amazement at the Prime Minister's gall in trying to execute a 180-degree shift in stance with as little drama as possible. Or was the surprise a manufactured excuse seized upon by some as another opportunity to express indignation at what might seem to be more evidence of the Prime Minister's increasing willingness to flout principles he previously espoused?
This case is very different, however, to the credibility-sapping episodes of last year surrounding Kim Dotcom and the GCSB.
There are mitigating factors in Key's defence. The Labour Party may love Opposition - as an exercise in masochism at least.
National in contrast has a bodice-ripping lust for power which is as core to why the party exists as its conservatism. Every National Party leader knows his or her survival is contingent on maintaining the uninterrupted delivery of power.
Key is no different. Nobody should therefore have been surprised by the content of Tuesday's positioning statement declaring which political parties National can do business with after this year's election.
Surprise aplenty there would have been had Key and his cabal of senior ministers who mulled over the carefully worded declaration reiterated the party leader's pre-election announcements in 2008 and 2011 that National would not be a part of any governing arrangement with New Zealand First which left National at Peters' mercy and able to pull the plug on any such administration.
National's allies, however, do not look like returning to Parliament in sufficient numbers to enable National to continue to rule in the minority as it has done since 2008.
Without Peters agreeing to offer his party's backing on confidence motions - or giving a similarly binding commitment to abstain when such votes are held in Parliament - the whistle will be blown on National's six-year occupation of the Government benches.
It is unlikely Key will incur much political cost from the change, however. The public well understands that MMP entails what David Cunliffe cleverly described as the "dance of the desperate".
Every time the Labour leader voices that refrain, it begs the question of what he would do if he was facing Key's predicament. Saying he would not have got himself into such a pickle in the first place is not really an answer.
Key's volte-face on dealing with Peters was already under way long before his week's official declaration - another reason why the latter was hardly a surprise.
Key has conducted a softening-up exercise over the past year or so to get National voters attuned to the idea of life with Peters again.
Whenever he was asked before this week about National not having the numbers on election night to govern, Key consistently predicted Peters was unlikely to opt for National because he had a strong dislike of the Prime Minister.
Moreover, Key kept saying he was convinced Peters preferred to strike a deal with Labour.
What Key was really saying was that he was no longer ruling out negotiating with Peters, but the latter would not play ball.
Then as now, Peters' response was to try to bury Key with bucket-loads of invective, claiming Key was trying to engineer the result of this year's election. Such diatribes only broaden Key's smile - and for one reason.
Peters has been consistent from election to election in stressing NZ First - should the party hold the balance of power - will talk first to the party with the most seats in Parliament.
That party will almost certainly be National. It is an advantage that National will not squander. The big question is whether National will be willing to trade the one bauble of office which Peters has never enjoyed (and which Labour cannot realistically offer) to secure his signature on a confidence and supply agreement.
Peters has been a finance minister, a foreign minister and a deputy prime minister. That leaves one large and obvious gap in his CV.
Will National seek to find ways around the significant constitutional obstacles to enable the leader of a minor party to do a stint as prime minister - obstacles such as could he realistically sack a Cabinet minister from the majority party?
There would be some benefits for National beyond the retention of power.
It is assumed that Key will quit politics some time in National's third term, assuming it gets one. Knowing he might get up to a year or so in the top job would be a huge incentive for Peters to ensure - unlike its predecessor in the 1990s - a National-NZ First administration actually goes the distance.
Meanwhile, Judith Collins and Steven Joyce could slug it out for National's top job, knowing the winner would not be crippled by becoming prime minister ahead of an election National would almost certainly lose.
This is all highly speculative. But it would be naive to assume such scenarios are not being discussed within National Party circles, not least because the notion of National being instrumental in enabling Peters to occupy the top floor of the Beehive (however briefly) is something the wider party would find very hard to swallow.
Moreover, selling the idea to the wider public would make the difficulties of gaining rapprochement with Peters look very easy in comparison.
