There are many good reasons to oppose the Iraq war. It's often difficult to explain to people why the war is a bad idea. Do you start with the moral consequences of the war? The thousands of dead American soldiers, the tens of thousands of dead Iraqis, the after-effects of depleted uranium?
But while these are valid reasons, they just don't quite hit the nail on the head. We're fighting this War on Terror, right? And why did we bomb the living tar out of Afghanistan? Because they're a failed state, that's why. Sorry Afghanistan, but you didn't have a monopoly on violence within your borders, you couldn't enforce laws within your borders, and those are two of the many conditions that lead to small groups (terrorist organizations, poppy-growing warlords, etc.) running amok.
So a bunch of Saudis attended training camps in Afghanistan, slam some planes into some buildings, and get bombed. We take out the Taliban (which is ironic because they were doing a better job of holding the country together than we are now), hook up the "Northern Alliance" with all kinds of support, and we're supposed to have a functioning state. That's not really how it's turned out, Afghanistan is still a joke of a state, with 2/3 of its population living on less than $2 per day, and 1/3 of its GDP coming from the harvesting of illegal crops. Afghanistan also produces 80 percent of the world's opium! Hooray!
Oh no, I was supposed to be talking about Iraq! Wait, Iraq is totally different than Afghanistan, right? No terrorist training camps, and a ruler who rules the country with an iron fist! Oh, am I talking about pre-invasion Iraq? I had no idea.
I hope I put those dots close enough together to connect. We've just traded in a strong state, counter-balance to Iran, and marginal success story (in relative terms), for a terrorist breeding ground. Did I mention we also gave the insurgents a great way to practice their attacks? It must have been so BORING in Afghanistan until 9/11, I mean, how many times can you coordinate bomb attacks on a mountain? The mountain ain't gonna shoot back and you can't get better. It's like shooting baskets in the driveway - it's good practice, but it's no substitute for real-game experience.
Let me say something about the United States. We kick ass, and on so many levels. We invented jazz music and fat people. But you know what we're really good at? Manipulating nutball governments. We can infiltrate them, play them against each other, overthrow leaders we don't like and install new ones, etc. We've been doing it effectively since the end of WW2. We honed our skill against the Soviets and relegated their entire ideology to 'Grade A Wacko' status. And now we're throwing all of that away??
If there's something that we as a country need, it's an effective anti-war strategy. We simply can't continue down the path we're on now. We'll never win a fourth-generation war. No nation probably ever will. I mean, we got our damn independence by fighting asymmetric warfare! But when I say "anti-war strategy," I'm not talking about peaceniks shouting slogans like "bring the troops home NOW!" or "OMG!1! BUSH IS TEH TERRORISM"