Moshe Dayan and Martin van Creveld both correct in their pronouncements that the Second Indo-China War was perceived as a case of the strong beating up on the weak. The very strong United States military "seen" by observers both in the U.S. and abroad for that matter as supremely and overwhelmingly so all-powerful, possessing advantages that the adversary [North Vietnamese and Viet Cong] had no valid response to.
One moment Charlie Brown. This perception was not totally valid when it came to North Vietnamese air defense. That air defense guarding North Vietnam from aerial attack by American tactical aviation flying in a strategic bombing mission [Rolling Thunder] very sophisticated and advanced perhaps without equal in the world at that exact moment [1965-1968].
"Supported by communist allies, North Vietnam fielded a potent mixture of sophisticated air-to-air and ground-to-air weapons that created one of the most effective air defenses ever faced by American military aviators."
Homeland air defense of the North Vietnamese heartland, NOT merely one of the most effective, PERHAPS THE MOST EFFECTIVE AND LETHAL!!
The North Vietnamese air defense [AD] consisting of that correct mix of weaponry to include:
* Fighter/interceptors. MiG-17, MiG-19, and MiG-21.
* Surface-to-air-missiles [SAM]. Exclusively so [?] SA-2 Guideline.
* Anti-aircraft-artillery [AAA]. Quad fifty-caliber [12.7 mm], 23 mm, 37 mm, 57 mm, 85 mm, and 100 mm.
Those larger caliber AAA guns some of which were radar guided.
An AD apparatus requiring a force of 700,000 troops to man and employ in combat.
An assemblage of radar, communications, aviation, missiles and guns an apparatus without peer, massive, dangerous.and to a degree unanticipated [?] by American planners.
In addition a 300,000 man quasi-military force dedicated to repairing in an expeditious manner damage as caused by Rolling Thunder air strikes, it reported that a goodly percentage of those laborers Chinese nationals [what percentage is unclear]!
A million man force and impedimenta [taken in totality] strictly in defense of North Vietnamese airspace, that gauntlet having to be run by American tactical aviation en route and homeward bound at all times lethal, North Vietnamese AD roughly in size to those air defense forces of Nazi Germany during World War Two [WW2], the memoirs of Albert Speer remarking that such a force was an enormous drain on manpower and resources.
To what extent the North Vietnamese AD was a mere imitation of the Soviet era PVO Strany or was adapted to local conditions [Vietnam] I cannot say. I think it is safe to say that the AD as encountered by American combat aviators in the skies over North Vietnam was far more advanced and determined than ever anticipated.