Everyone leaving the Aviva Stadium last Tuesday had the same questions on their mind. How did it go so wrong? Why did Christian Eriksen have the freedom of Dublin to tear our defence apart? Most importantly, should this be the end of Martin O’Neill as manager? Four years have brought many highs and many lows, with the Danish mauling by far being his lowest.A fortnight before, there were rumblings (which the FAI essentially confirmed) that O’Neill and assistant Roy Keane had been handed new two year contracts ahead of the World Cup playoffs. Any fan that didn’t have a short memory could think back to the build up to the European Championships in 2012, when the FAI gave Giovanni Trapattoni a new contract, despite a lack of success.While there was plenty of positivity before the Championships, afterwards doom and gloom reigned. Trapattoni had not even tried to win any of the three Irish games in Poland & Ukraine, a tactic which would continue to seep into his management until eventually getting sacked after a defeat in Vienna in September 2013.Flash forward four years and Ireland are top of their group after a magnificent performance in Austria. The four points from their next two games against Georgia and Serbia will put one foot on the plane to the World Cup in Russia. Shane Duffy scored early against Georgia, but here’s where the problems started.Ireland barely escaped Tbilisi with a draw, O’Neill had set up to defend the 1-0 lead for 86 minutes. Then, the following Tuesday, Serbia played Ireland at their own game, with the goal of avoiding losing, and winning 1-0. It all came down to a winner take all clash in Wales. For the victors, a playoff, for the losers, nothing. James McClean struck the most important goal of his career and there was still hope.Most fans were happy when we were drawn against Denmark in the playoffs. The whole country seemed to have the ‘it could have been worse’ sentiment. A freezing Saturday night in Copenhagen saw another awful performance from the Boys In Green (or white in this case), but it was another draw. All we needed now was a victory at home and we were off to our first World Cup in 16 years. Another early Duffy goal had us in the driving seat. We were just over an hour away from Russia. O’Neill sat back again. We conceded five times in 60 minutes. The Danes tore us to shreds and the wait continues.So we go back to the question: was this the manager’s fault?The detractors will say that O’Neill is stubborn. He refuses to change his tactics, his dealings with the media are awful, and that he’s a one trick pony. The evidence is not good for the Derryman. Away from home, he’s had some unbelievable results. Let’s not forget that this Ireland side held the World Champions Germany to a draw in Gelsenkirchen, and then beat them in Dublin. He masterminded a European Championship where we were close to eliminating the hosts. It seems Ireland performs unbelievably well when we’re the underdogs.It’s when we ‘need a result’ or travel to face one of the ‘weaker teams’ where things get a bit sticky. There’s an infatuation with playing it safe. Setting up for teams to try and break us down and then hopefully nick a goal on the counter attack for the three points. At the base of it all, it is this tactic and the managers refusal to deter from it, which cost us our place in Russia. If Ireland hold on to that 1-0 lead in Tblisii, they stay two points clear at the top of Group D. If they convert any chances against Serbia, they’re minimum three clear.If they grab an away goal in Copenhagen, they’re in control. If they show a bit of fight after going 2-1 down on Tuesday, it could have been very different.However, they didn’t and it wasn’t. O’Neill made some baffling decisions (like putting the hopes on a player that’s scored a goal every 30 or so games in an Irish shirt, and playing no midfield while 3-1 down) “Now there’s nothing for the ‘best fans in the world’ to do but cheer on whoever England are playing, and then go back to supporting the English Premier League next summer, again.This falls at the feet of the manager. Yes, he has a fantastic home record. Yes, Euro 2016 was fantastic for everyone involved with Irish sport. Yes, he’s given younger fans some of the greatest ever Irish international moments. There’s no production line for ‘the next generation.’ Plus, who are we going to get in instead of him?There are good points to defend O’Neill & Keane. However, they are easily countered. There is a production line for the future of Irish football. It is simply that the FAI would not like you to know about the League of Ireland. They’d rather that Irish teenagers are farmed over to English ‘academies,’ where 90% of them fail and return home with no education. In terms of replacements, the next European Championships in 2020 is the easiest to qualify for in history. We could appoint the manager of Roy of the Rovers and he’d get us there. It’s an attractive job.Of course, Martin O’Neill may not want to stay on as Ireland’s manager. His namesake north of the border is being heavily linked with a move to Scotland, Chris Coleman has returned to club management after a hugely successful stint at Wales. O’Neill’s relationship with the media is fractured. The attitude of the fans towards him has changed considerably for the worse. The squad he now has is weakened considerably by retirements.He now has plenty of time to consider his options but unfortunately, he can’t turn back time to Tblisi and change things to save his skin.