First, you have to understand the meaning of God. For me God is not person who lives or lived among us (just like Jesus). I think the term "God" is unnatural power we posses. Therefore, I believe God does not "look over us". We are responsible for our own actions. Children were born with horrible problems because of radiation. Example: After the nuclear bombs were fired at Hiroshima and Nagasaki, constantly Japanese children were born with problems. Still there are people suffering from the consequences of these nuclear bombs. So, "God" will not decide whether there will be nuclear firing but we do.