They have to be a certain variety of spy.
The diplomats other countries are evicting are spies described as "undeclared intelligence officers".
That is, spies listed by a Russian Embassy and pretending to be a kitchen hand or admin clerk, say, but who are known to be spies. If someone is declared as a spy they don't count. They are safe.
Other countries from Australia to Canada have managed to find at least a few of these undeclared spies. But Ardern looked and the cupboard was bare.
The 17 staff listed at the Russian Embassy were apparently all legitimately what they claim to be. We were an Undeclared Spy-free Zone.
It is likely Ardern never expected she would be in the position of having to defend New Zealand for a lack of foreign spies.
But this has caused some mirth over in Britain where the Telegraph and Guardian ran amused stories about New Zealand's valiant but fruitless efforts to join in on the spy-biffing.
Some are sceptical about the lack of spies - New Zealand is a Five Eyes partner after all.
The inability to find one indicates New Zealand either needs to improve its own spying game or our Russian spies are better than those in other countries at staying secret.
Either way, it was all very inconvenient for Ardern who had already been accused of going soft on Russia and taking too long to support Britain after its initial request following the nerve agent attack on former spy Sergei Skripal and his daughter Yulia.
Ardern is due to jet off to Britain in a couple of weeks and will have to ensure New Zealand stays on the free trade agreement carousel with the UK and the European Union. Having a spy or two to throw into the mix would help no end.
Between this she was dealing with allegations by National's Mark Mitchell that NZ First's Marcroft had tried to force him out of his involvement in the Mahurangi River Restoration Project in Warkworth.
According to Mitchell, Marcroft told him she was dispatched by a minister to warn him the project would not get money from the Provincial Growth Fund if he was involved and sought an assurance National would not ask questions about it if it did get funding.
Mitchell cried foul at what he saw as an attempt to gag him.
Marcroft left it to NZ First leader Winston Peters to defend her. Peters did so by saying Mitchell got the "wrong end of the stick".
When asked what the right end of the stick was Peters delivered enough sticks for a whole bonfire.
He said Marcroft had explained the project was not eligible for the fund because the Mahurangi River was in the Super City area so it was not strictly in a province.
After that, he said, the conversation appeared to veer off course – but he could not say what was said because he was not party to the conversation.
The Mahurangi River Project is a $4 million project to dredge silt from the river which flows through Warkworth to the Mahurangi Harbour.
The most likely explanation for the conversation Marcroft had was almost as bad as an attempt to gag the Opposition.
It is that Marcroft was trying to get Mitchell in a conspiracy of silence so they could sneak the Mahurangi River Restoration Project through the Provincial Development Fund and hope nobody noticed it did not meet the rules.
That version of events was somewhat backed up by Peters the next day when he said in Parliament that it was not the river's fault it was in the Super City and NZ First was "open minded" and trying to find a way around it.
Whether or not Mitchell's interpretation was correct, that combined with the Curran debacle likely left Ardern wishing she could gag her own Government ministers.
