Correct. And in the context of the article, the meaning of "foundation stone" is figurative.The foundation stone, or the fundamental basis upon which all else is built, is becoming unstable or non-viable.
Does that explain it ? Literal Meaning: In architecture, the foundation stones are the first stones placed into the ground, (nowadays of course, this is usually poured concrete), upon which the rest of the building is built. Good luck, John
