The violent crime rates quoted show that for rape, burglary, robbery with violence, assault, etc, the worst industrialised country is Aus, followed by the UK. For murder, the US is the worst.
Personally I have doubts, since the reporting methods differ. I spend a lot of time in both the US and Aus, and have never suffered any crime in either country, but the point of the study is that since Aus and the UK took guns away from the honest citizens, the rates of all type of crime soared, including the use of guns.
In those States of the US where permits are routinely issued for concealed carry of handguns, crime has dropped in all categories. It seems logical to me that what works should be adopted and what does not work should be dropped.
Unless all guns can be confiscated, something that the UK government, for example, never intended to do, disarming the victims merely makes the crims' work easier.
If the flightcrew and passengers are also emasculated, the terrorist will find his work easier too.