Something I have really wondered is, why aren't there stronger incentives to build mines with a mechanism that disables them after a certain time has passed? There must be tactical and strategical reasons which are regarded more important, but surely the party using them for defending their own land ought to have an interest in not having to deal with this threat for decades after the war has ended, and an aggressor who wishes to take over an area should have the same incentives.

Or are the reasons technical, that it is simply too difficult to develop a reliable mechanism for disabling them?

Modern landmines do have safety features like what you describe.

For example consider this Department of Defence policy from 2020: https://media.defense.gov/2020/Jan/31/2002242359/-1/-1/1/DOD...

“The Department will continue its commitment not to employ persistent landmines. For the purposes of this policy, ‘persistent landmines’ means landmines that do not incorporate self-destruction mechanisms and self-deactivation features. The Department will only employ, develop, produce, or otherwise acquire landmines that are non-persistent, meaning they must possess self destruction mechanisms and self- deactivation features.”

“ For example, all activated landmines, regardless of whether they are remotely delivered or not, will be designed and constructed to self-destruct in 30 days or less after emplacement and will possess a back-up self-deactivation feature. Some landmines, regardless of whether they are remotely delivered or not, will be designed and constructed to self-destruct in shorter periods of time, such as two hours or forty-eight hours.”

This distinguishes “self-destruct” where the mine blows itself up and “self-deactivation” where the mine disarms itself. The first is safer because it doesn’t leave explosive material behind, which could chemicaly detoriate and become unstable decades later. The second is used as a failsafe in case the self-destruct fails.

> Or are the reasons technical

They certainly were when the really old mines were made. Some of them are nothing more than just spring loaded pressure plates. But today modern landmines are much more sophisticated. Some of them can distinguish the seismic signature or a truck from a tank. There are also radio controlled mine fields where soldiers can remotely activate / deactivate the whole mine field as the threat evolves.

Cost/manufacturing complexity. If you are country struggling to defend your self you don't think problems in 30 years if today problem is does the country exists or not. Might be difficult to put your self to a small defending countries shoes which is absolute running our of resources.

As someone else pointed out, the short story is cost. Mines are cheap, make them more advanced and they are not cheap.

That said, even if the trigger is disabled, it's still an explosive device and should still be cleared (or never placed in the first place, as the Ottawa treaty says which the US, China, Russia, India and Pakistan are not a part of https://en.wikipedia.org/wiki/Ottawa_Treaty)

There is always the option to use battery (some modern mines use this),for example RAAMS.

The problem is of the enemy know you use only mines that work for max n hours or m days they just wait for n + 1 hours or m + 1 days.

There is a lot more to say about this, but there are probably people way more qualified than be here to explain it.

I'm guessing it's the latter, because you have to keep the mine-disabling mechanisms working and powered up through possible adverse weather and environmental conditions for long enough that the conflict has a fair chance of having ended.

That is exactly how modern mines work