Go read this.

However, the most important question is not the threat, per se, but whether we are at war. If we are indeed at war, the state has a qualitatively different set of options, regardless of the actual severity of the threat. The Bush administration is trying to justify extraordinary expansion of executive power not only because terrorists might hurt us (like hurricanes, or bird flu), but because we are literally at war. War powers aren’t justified simply as a function of the threat posed by the enemy. Congress doesn’t need to prove a threat in order to declare war. A war fought for convenience, greed, or strategic gain is just as much a candidate for war powers as a war fought to defend against a grave threat to the American way of life. One rationale for war powers is partly that when the country decides to fight, for whatever reason, it needs special resources in order to do so. The fact is that we’re not at war on terrorism, let alone against terror. Terrorism is a strategy. Actually, it’s a normative assessment of a family of tactics. In the current climate “terrorism” refers to any political violence the speaker doesn’t like. We aren’t at war with terrorism and we never have been. We were at war with Iraq, and now we’re fighting the Iraqi insurgency. We are engaged in a global struggle against terrorism by Islamic extremists. But we can’t even declare war on Al Qaeda, though the use of force against them has been authorized. We can’t declare war against Al Qaeda for the same reason that we can’t declare war against Columbia drug cartel or the mafia. These groups, however nefarious, aren’t states. If we were to destroy these organizations, new groups with the same mission would take their place. War is a metaphor for any all-out struggle against a serious problem: poverty, cancer, drugs, terrorism… Sometimes we use military hardware and tactics to further that struggle. Sometimes we even fight real wars as part of our strategy. The idea that the so-called war on terror justifies dramatic expansion of presidential power is extremely dangerous. Terrorism is never going to go away. If we accept that we are literally at war with terror, we are signing on to perpetual war for perpetual peace.