Wow, I think that your view of the Cold War and the technologies we developed during that time are somewhat naive. Washington DC is the most protected city in the world; it even has its own missile defense shield. The Pentagon was hit more than an hour after the first plane hit in New York. The Pentagon was already on alert. Even if your argument holds about the planes, and I certainly do not believe that it does, the plane could have easily been shot down. Then again, it becomes obvious that a plane was not what hit the Pentagon when you look at the damage and what was found. The claim is that the entire plane was vaporized. Anyone with half a brain could tell you that this is not possible.

We are currently in a permanent state of war; The War on Terror. We made over 3000 drone attacks violating the sovereignty of other nations in the last 4 years. We invaded two countries. We destabilized Somalia. We overthrew a democracy in Guatemala and are supporting a military junta. And, this should not be mistaken as a new aggressiveness. We overthrew nearly every country in Central America from the 1950s-1980s, Chile, Bolivia, some others in South America, Iran 2x, Iraq 2x, Vietnam, the Philippines, etc. When the Cold War ended, there was no reason to justify the defense spending of the Cold War and the events of 9/11 served to increase 'defense' (really a joke of a word as used) to Cold War levels.

We are the world's largest arms supplier. We spend more money annually on defense than the rest of the UN security council combined (China, Russia, England, France).