Should or could defense contractors/weapon manufacturers be held liable for bombs that did not explode when planned and the damages and costs that this occurs later?
Frankly I find the idea almost entertaining to bill them the direct (and maybe indirect) costs of for example a nowadays evacuation of a city because a bomb needs to be defused.
There's been some work on making munitions, especially mines, self-disarming. So after some period of time they won't blow up.
I think the main thing with preventing future munitions from causing problems like this is simply to avoid wars. So keeping NATO, the EU, the UN, and other organizations functional and influential is important.
(Even so, there'd be some amount of weaponry used within reserved training areas, but at least there the risk is known and civilians aren't in danger.)
Sometimes, as with mines, you don't necessarily want them to go off. You only want them to go off if triggered.
They would remain dangerous, however, unless they're the kind that renders itself chemically inert or otherwise incapable of exploding after some period of time has passed, in order to reduce risk of civilian casualties.
