Centers of power are clots in a society's circulatory system--inherently a non-adaptive reactionary element. The reason is simple. Our planet is a bio-system containing millions of species undergoing constant mutual adaptation. Every unit in a bio-system receives information, reacts to it adaptively, and this new learning is then transmitted to its neighbors. Social systems operate in the same way, except when power is concentrated. Then information is not transmitted on its merits but according to the power position of the transmitting unit. Therefore information necessary for successful adaptation to changing conditions is lost. Information coming from the periphery of the system--invariably the main source of new information about changing conditions--is ignored precisely because it comes from the periphery, a low-power position.
This is why governments--particularly large ones, and particularly centralized ones--are always the last to accept the necessity of adapting to changing conditions.
This is also why empires eventually collapse. As power becomes more and more concentrated, more and more authoritarian, its circulatory system becomes more and more sclerotic--information is transmitted less and less according to its merits and more and more according to the position of the transmitter. Large, over-centralized systems become like organisms without senses. They are blind, deaf, and insensitive. To compensate for this lack the leaders create artificial organs--spies and security agents. But these artificial organs are as blind as the real ones, for they're not seeking information that will help the leaders change adaptively, they're looking for information that will keep the leaders in power. They're not looking for new ideas, they're looking for signs of disaffection, of 'disloyalty'. This simply causes the leaders to compound and multiply their mistakes, and hastens the sclerosis of the system. The more internal spies a government has, the nearer is its collapse.
(The public sector is not the only area where concentration of power weakens the capacity to adapt to change. The poorer adaptability of power centers is the reason small firms produce 24 times as many new inventions per dollar as big corporations with big R and D departments.)
This is the reason democracy has swept the globe over the past century. Not because (as most Republicans and lack-wits within our government believe) a bunch of liberal idealists thought it would be more 'fair'--but because it's adaptive. It keeps the veins unclogged so vital information will keep flowing. It maximizes spontaneous innovation and creativity. It responds more quickly to crises, as we saw in 9/11, when the formal systems broke down and the informal networks performed superbly. A truly democratic system is better attuned to its environment, more responsive. It makes fewer mistakes. It prevents senile memory loss--like forgetting that Prohibition was a colossal failure that bred crime and violence; or like forgetting that small countries don't like being bombed, invaded, and occupied by big ones from far away, and usually make their invaders pay dearly for the privilege.
Unfortunately, our own system has been democratic in name only for decades, as checks on the power of the presidency have virtually disappeared, the influence of unelected officials and lobbyists has mushroomed, government by secrecy has become acceptable, the rule of law has been progressively weakened, and the electorate has become increasingly passive and submissive.
The most significant adaptive failure of the Bush administration--aside from revoking American democracy--has been the inability to recognize that all of today's major problems--global warming, ecological destruction, terrorism, economic inequality, the threat of pandemics--are international, and can only be solved through international cooperation, transparency, and the sharing of information and resources. The Bush administration is still living in the 19th century, when the nations of the world were still ignorant of their interdependence, and it wasn't quite as silly and shortsighted to think in terms of empire, national power, and military solutions.
Militarism in today's world is like a man's left arm deciding to beat his right foot into a bloody pulp in order to feel more in control.