Two of the most important things to keep in mind when it comes to problem-solving are as follows:
1. There would be no need for retroaction if we were an adequately proactive species. Both kinds of action are presently necessary for addressing problems (or symptoms), but preventing a problem before it even begins should obviously take precedence over addressing it as it emerges, over and over again. For example, police are currently necessary for arresting civilly restless people, but if those people were to have been brought up in a more methodical and socially healthy environment (we could expound upon this for quite a bit, but that would require its own post), then there wouldn't be a need for police -- or the need would be greatly reduced, anyway.
2. Even after a problem has emerged, and we are socially obliged to be retroactive about it, we should still focus on the source of the causal chain rather than the continuously generated symptoms, or end products of the chain. For example, no, we can't rewind time and raise hardened criminals correctly, but we can still do something so that more of them don't emerge in the future. This is definitely something that police do not do at all.
There are three approaches to problem-solving, and all are valid, depending on the scenario:
1. Prevent the problem from starting; use your foresight.
2. Once the problem starts, clean up its manifestations everywhere that they appear in as practical a manner as is possible. Don't overdo it, because you might generate more problems by focusing so much on symptoms.
3. Try to stop the problem at its source after it has started.