Ten years ago this week at a British army barracks in Aldershot, RTÉ Nationwide was given access to an area of the officers quarters where the Irish Guards Regiment was billeted.  

Prominently displayed on a wall was a portrait of Michael Collins, the IRA’s Director of Intelligence during the War of Independence against the Crown forces. 

Collins was 31 years and two months old when he signed The Anglo Irish Treaty at 10 Downing Street on 6 December 1921. It gave Ireland the status of "a self-governing dominion of the United Kingdom", similar to that of Australia, New Zealand or South Africa.

Northern Ireland would have the option of withdrawing from the Irish Free State within one month of the Treaty coming into effect (It had been created as a separate legal entity, seven months before, under the Government of Ireland Act).

The day after Collins signed the Treaty, Northern Ireland’s parliament wrote to King George V, seeking to opt out of the proposed Free State.

The previous summer, Collins had deep reservations when he was first asked to go to London for the Treaty negotiations. He knew in his bones that the 32-county Republic he had fought for might not be fully achieved. 

As Collins saw it, the result, hammered out during what were difficult, draining rounds of talks, offered Ireland "the freedom to achieve freedom."

But he anticipated there would be trouble back in Ireland over the deal.

Eight months later, on 22 August 1922, Collins was shot dead following an ambush at Béal na Bláth in west Cork - killed in his native county during the Civil War that broke out over the treaty.

Éamon de Valera, his former comrade, who declined the opportunity to lead the Irish delegation in the London negotiations and nominated Collins instead, was on ‘the other side’ during that conflict.

De Valera outlived Collins for another 51 years. He was a founding father of Fianna Fáil and served as Taoiseach and President. 

One view about Northern Ireland, voiced around the time of the treaty, proved to be wildly inaccurate.

It assumed that no more than four counties would join the North Eastern statelet, that it would be economically unviable and that reunification would follow in the "near future".

Leo Varadkar, just like Collins, is currently entangled in what seems like impossibly difficult negotiations. They will define his political career.

Are there times when Micheál Martin, maybe just like De Valera, is probably glad that, as opposition leader rather than Taoiseach, he has an off-stage rather than centre stage role?

Brexit is probably the most challenging diplomatic and far-reaching puzzle we have faced since Collins, Griffith, Barton, Childers, Duggan and associates headed to London in the autumn of 1921.

No allies or enemies, only interests

Viscount Palmerston, who built Classiebawn Castle in Co Sligo and nearby Mullaghmore Harbour was the British prime minister who said in the House of Commons in 1848: "We have no eternal allies, and we have no perpetual enemies. Our interests are eternal and perpetual, and those interests it is our duty to follow."

Such pragmatism has defined British diplomacy for centuries.

Theresa May is the unlikely prime minister, currently seeking to steer the United Kingdom through one of the most complex challenges since the end of World War II. 

Until David Cameron self-destructed, in Icarus fashion, by calling the Brexit referendum, she was relatively unknown. 

Former justice minister Alan Shatter might have an informed view about her as he had direct dealings with her for three years at EU Justice and Home Affairs Councils.

It was during her time in the Home Secretary role that vans were driven around different boroughs in London with the poster "In the UK illegally?.... Go home or face arrest."

Mrs May was such a mild, almost invisible Remainer during the Brexit referendum campaign that many Tory Brexiteers didn't actively try to block her in her successful campaign to succeed David Cameron as party leader and Prime Minister after he resigned. 

Her first slogan in the new role was "Brexit Means Brexit".

She called a General Election to strengthen Tory numbers and ended up in hock to the DUP.

She lost her voice at the party’s Annual Conference.

Her "let’s try to unite" Chequers cabinet meeting was a failure.

She has struggled through wave after wave of ministerial resignations, sackings and rows.

She often looks awkward and out of her depth.She is currently heading, full steam ahead, into a House of Commons vote she is likely to lose.

And yet. And yet... 

Events of the past fortnight would suggest that Theresa May now understands the island of Ireland issues that are at the very heart of the Brexit challenge.

Steve Baker MP, a prominent member of the pro-Brexit European Research Group, is one of those beginning to re-examine her actions.

She made him a junior minister in the Exiting the EU Office in June 2018, but a month later he resigned to allow himself follow his instincts "outside the tent."

A suspicious Baker and many Tories like him are now revisiting the May file.

She was, after all, a Remainer.

Could it be that the purpose of the snap general election Theresa May called in June 2017 was to strengthen her forces against the hard Brexiteers? 

The result was the opposite - she found herself totally dependent on the support of ten DUP MPs.

Not just Brexiteers, but negotiators trained in the toughest of all political environments where principles of "not an inch" and "no surrender" are badges of honour.

The Confidence and Supply deal that Mrs May agreed with the DUP just weeks after her disastrous general election showing seemed to be the beginning of an air-tight relationship, sealed by self-interest.

But before 2017 ended they had a serious bust-up.

Spurred on by the leaked story made public by my RTÉ colleague Tony Connelly, DUP leader Arlene Foster phoned Mrs May and forced her to stall the conclusion of discussions at the December EU Summit in Brussels.

On DUP insistence, Mrs May duly had the 'no border in the Irish Sea' provision included.

During the 11 months since, the DUP have been working on the assumption that in the Brexit negotiations Theresa May would see Northern Ireland treated as no different to Somerset or Sidcup.

The Confidence and Supply arrangement has up to now, been the gift that keeps on giving: Sir Jeffrey Donaldson, knighted in June 2016, is the busy DUP Chief Whip in Westminster; Sammy Wilson, appointed to the Privy Council in November 2017, is the ubiquitous DUP spokesman on Brexit; DUP-secured funds keep flowing towards Northern Ireland despite a closed-down Assembly.

And Secretary of State for Northern Ireland, Karen Bradley, has a "jump, how high?" relationship with her party's Westminster allies. 

The poison in the relationship now - and the word is deliberately selected - is because the prime minister seems to have returned to the stance she had in those Brussels Summit December 2017 discussions prior to the Foster phone-call.

Karen Bradley said on Thursday: "There is no deal without a backstop, and that's a point that people need to understand. This isn't an option. We have to have a guarantee for the people of Northern Ireland that there will be no hard border on the island of Ireland.

"The backstop is our guarantee to the people of Northern Ireland but none of us want to see it invoked, none of us want to see it in place…we need the deal, whatever your future relationship is going to be with Europe, whatever you think it should look like, you need a withdrawal agreement, and every withdrawal agreement, any withdrawal agreement would have a backstop in it."

Her comments came the week that the DUP’s deputy leader Nigel Dodds said "bin the backstop" and Arlene Foster again stated the backstop must go.

It would seem Karen (maybe encouraged by her friend, the prime minister) has grown tired of jumping.

The DUP's changed priorities

It took Ian Paisley, the frontman, and Peter Robinson, the strategist, nine long years to convert the DUP from a party of protesters who walked out the door from the Good Friday Agreement negotiations to a party of government.

Under the leadership of Arlene Foster and Nigel Dodds, the return journey has been completed in two years.

The Brexit referendum result was the outcome they did not expect.

The death of Martin McGuinness was the loss of someone who had the patience to stay the hard, difficult yards with them.

The Renewable Heat Incentive Scheme was an internal infection they did not identify or treat. The collapse of power-sharing was an unravelling they, and Sinn Féin who triggered it, did not quantify. 

The June 2017 election called by Theresa May completely changed the internal dynamics of the DUP.

Ten MPs at Westminster, used to the status of borderline irrelevants, became indispensable king makers.

The DUP's Assembly members, often the party’s most important connection and delivery mechanism for its support base, disappeared from view.

Last weekend’s DUP Annual Conference was a sobering reality check.

Party leader Arlene Foster became First Minister on 11 January 2016.

A year later the Assembly collapsed.

She has been out of her job for almost twice as long as she held the position. 

There is no obvious way back to work for her and a whole layer of highly competent MLAs, the likes of Simon Hamilton, Mervyn Storey, Edwin Poots, Peter Weir, Michelle McIlveen, Christopher Stalford and the new generation like Jonathan Buckley.

The more prominent and belligerent the DUP becomes in the Westminster Brexit power plays, the more untouchable the party becomes as a power-sharing partner at Stormont.

The DUP is comfortable in the outsider role. The deeper the hole becomes, the greater the tendency to be risk averse.

Last February the DUP almost broke out of the cycle.

Sinn Féin had modified some of its asks and Arlene Foster, encouraged by the likes of Edwin Poots, was shaping up to gamble of a deal to restore power-sharing.

The lack of active support from some of the Westminster 10 was a factor in the failure. 

And, as often happens, something obvious and mundane also had a role in scuppering the project. 

The availability of competent personnel is a chronic, ongoing weakness in the current DUP.

Richard Bullick, a key adviser for over a decade, took a private sector PR job soon after Stormont collapsed.

Other able characters like Timmy Johnston, Philip Weir and John Robinson are stretched by the new challenge of Westminster prominence as well as the Renewable Heat Inquiry that demands significant attention.

The space for reflection, the conditions required to allow for political courage and outreach, are missing.

It would seem there is no possibility of devolved government returning before the Brexit issue is settled.

Will Theresa May win the vote on 11 December?

I saw Theresa May close up at Queen's University Belfast last Tuesday.

Earlier that morning she was brought by car to Mid Wales for a series of meetings. From there she was ferried by helicopter to Cardiff Airport and she was then taken to plane through heavy winds and rain to Northern Ireland.

Her sales pitch resumed the following morning in Scotland; by early afternoon she was on her feet in Westminster where some of the most severe pummeling came from her own backbenchers. Her weekend included a trip to Argentina for the G20 Summit. 

During the week The Daily Mail columnist Sarah Vine was moved to write: "She (once) fired my husband (Michael Gove) but I admire May’s true grit."

All the signs are that, unless Theresa May bowls in something such as a U-turn on the backstop to appease the likes of the DUP during the Westminster debates before the Brexit vote, she will lose.

So what then?

If she suffers a crushing rejection in the 11 December vote, there could be pressure on her to resign.

But the chaos within the Tory party may prove to be a help to her.

Just as the Tories have struggled for two years to agree a Brexit strategy, they do not seem to have an obvious May replacement capable of binding the party and winning the confidence of the electorate. 

John Mann, a Labour pro-Brexit MP, said on Saturday's BBC Radio 4 Week in Westminster programme: "One thing that surprises me, she and the people around her seem very bullish, more so that seems logical at the moment, which suggests to me they do have a Plan B….a real Plan B.

"I'm not saying one that will get through, I don't know because I don't know what it is, they have not told me. But there is definitely a Plan B there. They could not possibly be as confident as they are now without a Plan B. There will be a second vote. This one is going to go down. There will be a second vote, if she survives."

Anna Soubry, the Conservative pro-Remain MP, was a guest on the programme too.

She said: "I absolutely agree with you. You must be right. There must be a Plan B. Obviously there is because they know the maths, they know exactly where the numbers are on the Conservative back benches.

"It could be that this Plan B is some tweaks to the political declaration… 

"There is a confidence about her which I think is really interesting. As I've looked at the Prime Minister, I've thought, does she know something that we don't know? It also struck me that maybe she is saying to herself 'I've given this my all, I've done my best and if they won't have it, then I'll go'."

The most obvious scenarios all have a common thread.

They guarantee the continuation of uncertainty and chaos.

If Tuesday week's vote goes against Theresa May there may be an effort to tweak some elements of the package and put it before the Westminster parliament a second time.

There could be a push to oust the prime minister.

Some will continue to press for a People's Vote and the reversal of the Brexit decision. 

There is no obvious end of the bickering in sight or no formula that would attract clear majority support.

The 52/48 margin in the 2016 Brexit referendum reflects an almost evenly divided nation.

Statistics published during the week showed a fall off in EU citizens coming to the UK and an increase in the number of EU nationals leaving.

But this coincides with a sharp rise in the incoming numbers from non-EU member states including Pakistan, India and Nigeria.

So the 'outsiders' factor continues to exert pressure and tension in stretched sectors such as schools, housing and healthcare.

Imagine if in the febrile Westminster bubble that no solution could be agreed before 29 March 2019, and deadlock leads to the UK leaving the EU without any deal.

Would traffic continue to flow between Dover and Calais?

Would Irish exporters be able to use the land bridge as their unfettered stepping stone to the mainland Europe market?

Would goods going directly to France and other mainland Europe ports be allowed to move as before?

Or would new arrangements be expected along the EU's only land border with a large country that just left the club in strained circumstances?

What would be the EU and the World Trade Organisation stance on tariffs and regulatory arrangements and variations?

The impressive English historian and academic Peter Hennessy, who is an expert in the history of government, assesses matters in this way: "There are several 'capital Q' questions all swirling, one into the other, they all feed off each other.

"There's the European Question obviously, which has re-opened Britain's place in the world question, which we have been grappling since the Suez crisis in 1956. It has reposed the Irish question in a new form. It is posing again the very union of the UK question because if it goes wrong, if it is a tough Brexit, it could well fuel the separation pressures in Scotland and a Referendum in the 2020's.

"It is stress-testing our model of political parties because left/right can't handle it. It has also raised the 'condition of Britain' question because the referendum drew up in stark relief the difference in life and life chances across the kingdom."

And so we turn our attention to Westminster.

It was during the opening days of December 1921 that Michael Collins was in London, reluctantly involved in impossibly difficult negotiations, in which Northern Ireland was a factor.

We thought we had found an agreed understanding about it, helped by a European framework. The vast majority of us, north, south, east and west were happy about it.

Ninety-seven years on, tensions within the British Conservative Party have dug deep into the wardrobe of history and put the Irish factor and other baggage on the table.

Sometimes it seems that, just as they don't know what they are doing, they don't know what they have done.

Hopefully Theresa May does.