Hydrogen bombs have never killed anyone. But we can imagine the consequences of a war in which they are used in anger. Statistics can be misleading. Take air crashes. I'm a member of the Qantas frequent flyer club, an airline that has never had an accident.
Circumstances can change quickly.
Until recently Concorde was regarded as a paragon of air safety. Two decades ago virtually everyone, weather forecasters included, thought that hurricanes never hit England. The only nation spending any sensible amount on asteroid defence is the United States. In effect we too, need to declare war on the heavens. It's really good to see Britain taking a leadership role in NEO detection, but what is also needed is for Australia to become an active participant again.