For decades the world has struggled with what to do about unexploded land mines and cluster bombs killing innocent civilians, even years after a conflict has ended. The problem is that a significant percentage (10% - 40% in the case of cluster bombs) of these weapons do not explode when they are deployed, and instead blow up later on when they are disturbed by a person or animal. They also result in creating dead-zones that cannot be used for other purposes after a conflict because of the risk of unexploded ordinance.
Various treaties and proposals have been floated to ban these weapons, but they are not going to go away that easily. First of all, leading nations such as the USA, Russia and China (which also lead the production and sale of these weapons), refuse to participate in these treaties, and secondly, even if they do these weapons will still probably be used by outlaw nations.
While trying to get everyone to agree not to use these weapons is a noble goal, it is not very realistic. The genie is already out of the bottle. Putting it back in is very hard.
Instead, there is a more practical solution to this problem: Timed Deactivation. The basic idea is to redesign these weapons systems such that they simply cannot explode after a set period of time unless they are manually reset. A simple way to achieve this is to design them such that a crucial part of the weapon corrodes with exposure to naturally present environmental air or water over time. Or alternatively there can be a mechanical switch or even a battery powered timer. In either case, after a set period of time (1 month, 6 months, 1 year, 3 years, for example) the device simply decays and can no longer explode without a replacement part. In the best case, after an even longer period of time the explosives in the device should decay and be unusable, even with a replacement part.
Designing these weapons to self-destruct safely is a practical measure that should be part of the solution. Nations that refuse to agree not to use such weapons should at least be able to commit to designing them to deactivate automatically in this manner.