The SA was not destroyed--it was "incorporated." The prime target of the "night of the long knives" was not Roehm but von Schleicher, the figure most likely to head a Wehrmacht action against Hitler (Roehm and his minions were a sacrifice to appease the High Command). The Nazi regime was a "paramilitary" *police* state. It allowed the HIgh Command no political role whatever, and always feared it, with very good reason, as the only group willing and able to conspire against Hitler. That fear was fully shared in London, Washington, and Moscow and was central to the Berchtesgarten/Munich Accords, the "Unconditional Surrender" strategy, and the extermination bombings--the fear that a new 1918-1919 revolution would follow Hitler, the fear that, as Coulondre and Hitler famously agreed, "the only winner would be Trotsky."
Shane Mage
"One can never agree, in any kind of war, with events that take the lives of innocent civilians. Nobody could justify the attacks of the German Air Force on British cities during World War II, nor the thousands of bombers that systematically destroyed German cities in the decisive moments of the war, nor the two atomic bombs which the United States dropped on Hiroshima and Nagasaki in an act of pure terrorism against old people, women and children." (Fidel Castro)