Intelligence failures

"Certainly, spies are everywhere, but were they ever any use to anybody? Western intelligence didn't know the Berlin Wall was going up; Soviet agents didn't have a clue it was coming down." Robert Lochner, American journalist in Germany, son of Louis Lochner who was AP correspondent in Berlin until 1941.   

A brave spy risked death to tell Stalin that Germany was about to invade Russia.  Stalin had him killed.  A spy told Roosevelt that Japan was about to attack. Netanyahu was informed beforehand of the Hamas attack and did not prevent it.  Whether these were examples of incompetence, inability to accept the truth or occult Machiavellian stratagems Lochner's point is good.