The sector was threatened long before Thatcher. There's an oft quoted remark (that I'm not sure is true) that just as many pits were closed under the previous Labour government than under Thatcher. In addition to coal being transported from New Zealand, the Warsaw Pact, that bastion of the worker, had coal shipped from Poland as well. In many ways I feel it was the last gasp of the workers in a dying industry but the way that Thatcher went about with breaking the NUM basically left whole communities devastated and thousands unemployed with no prospects. I think a 'victory' for the miners wouldn't be to keep the pits open necessarily but to slowly phase out all but the still profitable pits, and there were more than people think, whilst training former miners and developing their local communities so that there's alternative employment and not so many people are left destitute by the crisis. In other words, slowly wean them off the drug instead of the disaster that was going cold turkey.