John Key had a good and easy relationship with President Obama. They may have come from different positions on the political spectrum, but they shared similar values and seemed to like each other.
Our Prime Minister's relationship with President Trump may not, though, be so easy. There are so many aspects of the new President which are problematic. And John Key will not be the only leader across the globe who will be unsure, at this point, quite what to expect.
There will be many foreign capitals trying to assess whether the Donald Trump they saw as a campaigner for the presidency is the same man as will take up residence in the White House. They will be asking themselves how they should respond to a man who seems to fly in the face of so much of what they might normally expect from an American president.
Are they to take seriously his proposal to build a wall on the Mexican border? And what about his promise to deport millions of supposedly illegal immigrants? Even more seriously, has he really committed to re-introducing torture, including waterboarding, as a counter-terrorism weapon? How many of America's usual allies would willingly align themselves with a publicly declared policy of that kind?
And what are they to make of a President who takes such a cavalier attitude to the constitutional proprieties? Who seems so keen to use his position to enhance his personal business opportunities? Who is so clear in his intention to abolish Obamacare so that poor families are left without access to medical care - and to stack the Supreme Court with his own nominees in order to roll back the policy advances on social policy issues that have been made over recent years? Whose initial appointments include those whose records are sullied by racist attitudes - appointments that have been welcomed by extremist bodies?