There is a pattern which often follows reports like the one published at the Manchester Arena inquiry on Thursday.
Those who receive the most damning criticism often remind us that the "benefit of hindsight" is a luxury available to the former judges or terrorism experts heading reviews, but not to people on the ground who could have prevented the terrorist attack. Few people are saying that this time.
ITV News Global Security Editor Roohit Kachroo on the lessons that should have been learnt
Because when Salman Abedi detonated a homemade device packed with shrapnel in the foyer of Manchester Arena as an Ariana Grande concert finished on May 22, 2017, everyone had the hindsight which followed the Westminster Bridge attack two months earlier.
There was a heightened sense of awareness of the threat from terrorism in the UK after Khalid Masood killed four and injured dozens more close to Parliament.
The attack in London should have reminded everyone that high profile locations were vulnerable from terrorist attacks - venues just like Manchester Arena.
Yet there was complacency. British Transport Police officers who should have been patrolling the arena had decided to take a long break instead - two officers drove out to buy kebabs, leaving no one on duty at the time Abedi approached his final position.
Chief Constable Lucy D’Orsi says the force has been “reviewing procedures”. The chair of the Manchester Arena inquiry has called for action to better protect large venues.
Following campaigning by Figen Murray, the mother of victim Martyn Hett, the government is considering new obligations for the owners and operators of large organisations and venues to do more to consider pre-emptive action to protect from terrorism.
Arena operator SMG has said it will “continuously challenge [itself] to be better”.
Showsec, the arena’s security provider, said it has “learnt lessons”. But for all the focus on ‘Martyn’s Law’, systems were already in place which could have prevented the death toll at Manchester Arena from being so high.
Today’s report is not only about what should be done now, but what wasn’t done then.
And there are so many areas which it needs to cover - this is the first of three volumes which the inquiry will publish.