She'll have to play Union card very carefully to stymie break-up of UK
In Theresa May's first speech as Prime Minister - in which she stressed the personal importance to her of the word 'unionist' in the title of the Conservative and Unionist Party - she echoed the words of David Cameron to the UUP conference in 2008.
"I've never been a little Englander," he said. "I passionately believe in the Union and the future of the whole United Kingdom. We're better off together - England, Northern Ireland, Wales and Scotland - because we all bring our strengths to the mix."
His speech was made at a time when the Conservative Party, uncertain if it could secure an election victory over Gordon Brown in the next couple of years, needed to try and win extra seats in England, Scotland and Wales.
May's position is much more complicated: Scotland and Northern Ireland voted Remain in the EU referendum and both Sinn Fein and the SNP are upping the ante in terms of wanting to break away from the UK. She will also be aware that the rise of 'little Englander' nationalism could fuel the view that England would actually be better off without Scotland and Northern Ireland.
Her task now is to try and play the Union card to prevent the break-up of the United Kingdom, while knowing that the SNP plans a second independence referendum at some point anyway.
But the only way she can play that card - allowing her to wrong-foot Sinn Fein (and her calculation will be that there is little likelihood of an anti-Union majority in NI anytime soon) and buy time with Scotland - is to ensure that Brexit is so watered down that, to all intents and purposes, the UK may just as well be in the EU.
Yet in so doing she will enrage the right wing of her own party, breathe new electoral life into Ukip and end up fuelling the very 'little Englander' insularity that she's trying to curb.
Her appeal for a "Union not just between the nations of the UK but between all of our citizens - every one of us - whoever we are and wherever we're from" also echoes Cameron's 2008 desire to "celebrate Britain for what it has been, for what it is today and what it can be in the future".
But the UK and Union she has inherited is, as the referendum graphically indicated, a country seared and scarred with division: social division, constitutional division, geographical division, cultural division, economic division and, most crucially, a toxic division over the EU.
The irony of Cameron's legacy is that he has left the UK and Union more disunited, fractious and unstable than at any time since the Home Rule crisis of the late 19th century.
May's words yesterday were well intentioned, but she will know that Brexit and a stronger UK don't go hand in hand; that a back-pedalling on Brexit and a stronger UK don't go hand in hand, and that anything in between will simply destroy her authority as leader and Prime Minister.
She faces a huge challenge: greater even than Churchill's in the Second World War. At least he had a United Kingdom and a common purpose to rely on.