Fetching details from the dictionary...
land mine
topic that sets someone off; sensitive topic; taboo topic; trigger
something that seems fine at first but turns out to be very bad (e.g. product, business); booby trap; pitfall
専門家が地雷を撤去した。
Specialists removed a land mine.
戦争で多くの対人地雷が埋められた。
Many anti-personnel land mines were buried during the war.
地雷原では常に爆発の危険がある。
There is always a risk of explosion in a minefield.