Discussion Board Manchester attack

Your initial post should be 500 words or more. I will be looking for key insights and unique analysis in your posts, just not regurgitation of news reporting. Don't waste your time and my time unless you're going to bring fresh, unique, and your own critical analysis to the post. Please cite all sources in your initial post. I expect you will do some independent research outside of the information I am providing below. However, don't over-rely on sources. I want to see your analysis steeped in your own expertise after you have done your research.  MUST HAVE IN-TEXT CITAIONS AND REFERENCES MUST MATCH!! 

ARTICLES:

http://www.telegraph.co.uk/news/0/manchester-terror-attack-everything-know-far/

www.theaustralian.com.au/news/world/the-times/manchester-bombing-latest-attacker-planned-for-a-year/news-story/06f59aba8950bca59e74a9b5adfe2780

http://www.npr.org/sections/parallels/2017/05/23/529645904/manchester-bombing-is-europes-12th-terrorist-attack-since-2015

http://www.cnbc.com/2017/05/23/sophisticated-weapon-used-in-manchester-terror-attacks-is-disturbing-says-security-expert.html

The key questions I would like your opinion and analysis on in your initial post:

1. Where did you think UK authorities went wrong - if they were wrong - in preventing this attack? Be specific. Was this attack preventable and how?

2. Looking at the attacker(s) involved in this event, what are the key takeaways about their recruitment, training, radicalization, planning, and execution?

3. As the terrorist threat evolves globally, and as terrorists modify their TTPs, what unique lessons-learned do we take away from this attack? Is there policy or security measures we should modify in response to this attack here at home in the U.S.?

Give me the best you can. A lot of valuable bonus points are available!