Why is it important to weigh the risks of any action against its benefits?

It's important to never ignore the risks and to weigh them against its benefits because it can help a man determine what is the right, the best, the most humane, etc, thing to do. A popular example would be the dropping of the bombs that ended WWII. The risks and benefits had to be weighed to figure out what he thought the best thing to do should be. In its benefits, he ended the war and saved many american and japanese troops, but with the risks came many deaths of innocents. And as most know its still an ongoing debate on whether it was right or wrong. Sometimes it can be hard but its still important to weigh the risks against its benefits.