Politicians with a tenuous grip on their party's leadership swan off overseas at their peril. But Mr Key remains the National Party's greatest asset, even if he is not quite the breezy persona he was even a year ago. He had nothing to fear and everything to expect from another Royal hobnobbing.
It seemed only recently he was in Westminster Abbey and among the guests at the wedding of the Queen's grandson Prince William to his beloved, Kate Middleton.
And so back went Mr Key and wife, Bronagh, this time to celebrate Her Majesty Queen Elizabeth II's Diamond Jubilee. After all, such occasions, amid pomp and circumstance, among world leaders and men and women of influence - along with the smattering of "glitterati" that has attached itself to the Royal coat-tails - are perfect for reinforcing the natural order of things. A photo opportunity here, a Royal audience there, a brushing of shoulders with fame, fortune and superannuated pop stars, sends warm vicarious shivers of self-congratulation up the spines of readers back home. We all like to be noticed, at the centre of things, and if we cannot personally be so disposed, then the next best thing is if our leaders can in our stead.
My Key performs this role with enthusiasm, sometimes even visible, not to say voluble, excitement. But if the occasion of the Jubilee was generally held to be a great success, from the Thames River procession with its myriad craft, including New Zealand's Maori waka, to the star-bursting concert outside Buckingham Place, it is doubtful it will prove a highlight of Mr Key's premiership.
This is because of the insistent, party-pooping political rumblings from back home. Mostly they concerned the growing and strident opposition to a poorly orchestrated and inadequately foregrounded education initiative, based on the notion - validated, incidentally, by a good deal of research - that class size is not as significant a factor in educational outcomes for pupils as is teacher quality.
Between this theory and current teaching practice, however, are decades of adherence to a "smaller classes leads to better learning" philosophy, an education sector already partly alienated over another debatable imposition - National Standards - and of course the self-interest of teachers pricked raw and liberally salted with loose talk of trade-offs between quality and quantity. Into this piquant brew of potential job losses was stirred the anathema of performance pay.
If conducting a crisis-management telephone conference from London was bound to put a damper on Mr Key's trip, then while perhaps good for the political ego, his visit to Germany may not have filled the prime minister with joy and optimism either.
Europe, still a significant market for this country and a major world trading bloc, is almost dysfunctional.
German Chancellor Angela Merkel is doing her best to discipline the wayward fiscal spend- thrifts of southern Europe, while her most powerful ally - France - looks to have changed political colours, with the increasingly likely eventuality it will soon have a pro-growth Socialist government.
Spain's major banks have been bailed out, but this has not entirely lifted the gloom. Italy teeters on the brink amid the latest revelations of former prime minister Silvio Berlusconi's sexual shenanigans. Portugal and Ireland are not much better off and, as Mr Key turned to fly back south, Greece was preparing for this weekend's critical re-run elections which, in a worst case scenario, might see the eventual disintegration of the euro zone.
None of this is good news for New Zealand and the best spin Mr Key was able to bring to it, on his return, was that comparatively speaking this country was in a much better position, debt-wise, than the troubled nations of Europe. Which, all-in-all, is a pretty ineffectual political trophy with which to re-enter the domestic fray - the site of increasingly stubborn resistance to the prime minister's once all-soothing pronouncements.
Diamond Jubilee or not, it seems that the Big OE can still spell trouble for even the most popular of politicians.
