It was public doctrine in textbooks, taught at university. The warnings about moves at the chessboard (which in diplomacy often are issued in advance, contrary to chess) have been stated for decades, publicly and face to face. The products of the propaganda machine were quite reachable, and not really ambiguous.
Really, that «few saw» is farcical.
Edit: and it is quite worrisome to think that said "doctrine" is now implemented only up to a small fraction, and those expressions suggest blindness not just about the current actions, but the openly planned, stated future ones.