So, the backstop is integral to the EU in preventing a hard border on the island of Ireland.
Yet if we go full Boris and leave with No Deal then a hard border is an inevitable consequence.
Am I reading the situation correctly?
Broadly yes (I think although there is a lot to it), no doubt there wlill be others better able to articulate it but my understanding is...
Basically the EU (SM & CU) obviously requires hard borders at its edges to third parties or the whole system doesn't work, when we leave NI becomes a third party country to the EU and thus a hard border with customs controls is needed (the EU did suggest the easier way round that would be to put the border in the Irish Sea (not that its any easier for them but obviously from an infrastructure PoV it would be for us) but due to the government being propped up by the nutjobs in the DUP this was never really an option).
Basically the backstop seems to be a legal mechanism that the EU can use to hold us to our promises (inserted at our request as May thought she could get it through parliament), possibly more exacerbated by the fact that since 2016 we have shown the good faith and trustworthiness of the most rapid divorce lawyer in our negotiations, thus they don't really trust us very much! The EU also seem rather more aware of the possible negative effects on the GFA (a hard border would royally fuck it up basically), something our politicians seem unable to comprehend, or in fact seem unable to comprehend that the RoI is no longer part of the UK.
In the case of no deal, in theory we don't need a border (although to do away with it would rather fly in the face of the oft spouted 'taking back control'), however the EU would like still need to impose one as obviously for the reasons noted it would fly in the face of the SM/CU. Add to the fun the fact that it would leave an open border for every Tom, Dick, Harry and immigrant to enter NI and thus the UK unfettered (if I were the EU I would be bussing people from the med to the Irish border and letting them crack on with it) it also rather defeats a further plank of the Brexit argument.
Final fun fact for the day, the much derided £39bn 'divorce bill'* was calculated months back, since which our noble leaders have managed to tank the pound even further, I wonder what that figure is now on a roughly £1-1 euro exchange rate, although this coule be offset by the fact that we have already paid some of it off so who knows.
The amusing bit is that Johnson voted for Mays deal earlier in the year as at the time she promised to resign if it passed, so essentially he is now wandering around saying something is crap that he voted to support in parliament a few months back, integrity huh!
*Which we possibly could not pay, but were we to try and wriggle out of it would further erode our already almost non-existent international standing and basically make us the Jed McCrory of international politics.