Apologies for the off-topic detour. I've never forgiven the US unintelligence agencies for their idiotic and national-security-damaging behavior before, during, and after the fall of the USSR.
Some of the foreign agencies are more competent. The UK agencies aren't competent either, though.
Points well taken; I should have said "sometimes" as "often" is too positive. However, you probably would agree that the US has at least two marks making assessment of the Soviet Union your best example of failure: 1) uniquely hostile to any philosophy that might be favorable to labor and 2) political interference in the assessment process itself. On the latter point Jerry Ford's insistence and Bush one's complicity in the Team A and Team B controversy when he was CIA chief is the best example, along with Bob Gates' appointment to clean up the shop applies to assessment of the Soviet Union. Another example of classic meddling in CIA work is the pressure by Dick Cheney in advance of the Iraq War. That's where Trump's general ignorance misses an effective point. Also I'm sure you know about NSC-68's argument a defense industry stimulus by the Cold War would create sustained American military involvement in the postwar world. Truman deliberately created the forces Eisenhower warned us about in his farewell address. Finally, Trump is doubtless waging that traditional war against any agency opposing his preferred version of reality. What is now unusual is the intelligence bureaucracy is fighting back.
You must be an historian. Just as "My arms are too short to box with God,"...I drop my king.