You lay those mines with an aircraft or missile, I'd suspect.
It's like a sleeping cluster bomb - one of the worst (in terms of humanitarian problems) antipersonal mines out there, the Russian PFM-1 butterfly mine [0] is a cluster munition that simply floats to the ground and stays there.
The PFM-1 also has a deactivation mechanism but it didn't work well enough in practice.
Deactivation mechanisms are one thing but what the explosives do over time is a big deal, even if the trigger/fuze is guaranteed to be inert after a short time.
Explosives can be like mayonnaise, they can separate after a while, forming sensitive mixtures, making the 'inert' mine suddenly dangerous again.
It's like a sleeping cluster bomb - one of the worst (in terms of humanitarian problems) antipersonal mines out there, the Russian PFM-1 butterfly mine [0] is a cluster munition that simply floats to the ground and stays there.
The PFM-1 also has a deactivation mechanism but it didn't work well enough in practice.
Deactivation mechanisms are one thing but what the explosives do over time is a big deal, even if the trigger/fuze is guaranteed to be inert after a short time.
Explosives can be like mayonnaise, they can separate after a while, forming sensitive mixtures, making the 'inert' mine suddenly dangerous again.
[0] https://en.wikipedia.org/wiki/PFM-1_mine