[nishonia]

What you are describing might be true of other countries, but that isn't the way it works in the US. You aren't too far off on the military training issue, immediate obedience to orders is incredibly important - at the lowest ranks. The US military has an extremely long institutional memory, and over a couple hundred years they've figured out a way of doing this that works pretty well. The conditioning for immediate obedience to orders and illusion of immortality wears off after a couple of years, right around the time that personnel start picking up rank and assuming positions of responsibility over others. So by that time they won't be charging any machinegun nests, they'll be in a position to order others to do so - at this point it should be clear to you why filtering out intelligent people is a bad idea :) The conditioning wears off, but you can't fix stupid.

[sosuke]

I think you're right, and as someone else said the commanders, chiefs and detectives are promoted, not hired in, which makes limiting intelligent hires a terrible plan for longevity.