This is the Achilles heel of the matter, in my view.
However, every security system had an Achilles' heel: the phone line.
People will not miss anything that gives you an Achilles' heel.
I mean, the great Achilles heel of that was people not knowing whether to say yes or no.
The Achilles heel might well be in the public education sector.
During the whole season, the true Achilles' heel was the defensive game.
Food and women, in that order, are his Achilles' heel.
Everyone has a professional Achilles' heel, a point of vulnerability.
"Perhaps we have found an Achilles' heel in our powerful enemy."
"If the ranch had a financial Achilles' heel, what would you say it was?"