Well, 'risky' knowledge seems generally easier to research than the knowledge to contain it. See the atomic bomb vs. the missile shield, over 60 years later. It's easier to destroy than to create.
Also, humanity isn't exactly united in aiming our progress in the right direction. However, I don't think we'll go extinct any time soon (that would take nothing less than a very big asteroid).
but we didn't and still don't necessarily need a missile shield to prevent the atomic bomb from destroying us. we had, and used, diplomacy, locked weapons silos, etc
Also, humanity isn't exactly united in aiming our progress in the right direction. However, I don't think we'll go extinct any time soon (that would take nothing less than a very big asteroid).