Encryption software and hardware has to come from somewhere. Maybe it's not the US. What then - China, Russia, Great Britain, or perhaps Israel? Who else has military grade capability? And who won't backdoor it?
Recently I've been reading history. The Sioux warrior Red Cloud shut down the Bozeman trail. Then the weight of 10 million Americans overwhelmed his nation of 20,000. It's hard to grasp vast differences in scale. The NSA isn't Apple or Google.
It can raise billions to combat bogeymen and need not turn a profit let alone answer to stockholders every quarter. It can appeal to a patriotism that runs far deeper than mere brand loyalty. Nobody is going to put their life on the line for iOS.
Nevertheless, the main game at Bletchley was Colossus (https://en.wikipedia.org/wiki/Colossus_computer) which allowed the decryption of high level planning communications between German High Command and the government. By main game, I mean that it was the work on Colossus which created the first machines recognisable as computers. This was the codebreak that truly gave the Allies the ability to outmanoeuvre the Germans at a strategic level. There were no German strategic victories once Colossus came on line in late 1943 (the last substantial German victory in the war was https://en.wikipedia.org/wiki/Third_Battle_of_Kharkov#Manste... in March 1943), compared to numerous Eastern front victories after the Allies started to successfully decrypt Enigma.
Of course we as geeks tend to overestimate the effects of successfully breaking codes. The results are not always positive - for example Rommel's offensive in Africa originally succeeded because Enigma intercepts indicated that he had been told to sit tight, but Rommel decided by himself to launch an offensive. The English were caught flat-footed, and very nearly lost North Africa as a result (https://en.wikipedia.org/wiki/North_African_campaign#Allies), with only a well-fought defensive action by the Australians stationed in Tobruk saving the day.
> Properly implemented strong crypto systems are one of the few things that you can rely on.
Of course you can infiltrate the facility to access the keys or attack the management systems with zero day exploits. But every bit of protection is worthwhile, because it might be the crucial step that the NSA is not able to break with the assigned budget.
[1] http://www.theguardian.com/world/2013/jun/17/edward-snowden-...