David Cameron was in Northern Ireland last Saturday for a flying visit.
On Monday, I asked Boris Johnson, Jeffrey Donaldson and Theresa Villiers about that threat as they visited Boomers Industries in Lisburn. Not one of the three believed there is such a danger to the UK (full links to the videos below).
Mr Cameron and his convoy of bullet-proof vehicles swept into the farm after an earlier visit to Bushmills. There was a strong sense of the power and prestige of Downing Street. And yet in a way he cut an isolated figure compared to Boris on Monday. There was no local MP (Ian Paisley Junior) or secretary of state (Ms Villiers) or first minister (Arlene Foster) to greet the prime minister.
Boris was met by all those eurosceptic politicians, and another one – the MP for Lagan Valley (Mr Donaldson).
I put this point to Ms Villiers and she rejected my characterisation of any isolation of the PM.
In a way she was right. Mr Cameron was over to campaign against Brexit, so it would have been odd for him to be accompanied by supporters of it. Boris was over to seal the Wrightbus deal, which had nothing to do with the EU campaign.
But even so, events have developed in a way that means Mr Cameron was unable to count on public support last Saturday from politicians who might otherwise have seemed natural allies. It was a reflection of these odd times.