It's a universal constant

People will die at the hands of other human beings. But it will be quite hard to conceal a ballistic missile launch, or to deny a role in it, and so the perpetrators will go to jail for a very long time. If they're stupid enough to launch from a different country, then they can expect airstrikes or a ballistic missile in response.

So we have to rely on the innate goodness and self-preservation of humans. It's the same reason we don't have (too many) incidents of people driving cars at high speed into crowds.