If we knew then what we know now...
The question making the rounds of Republican candidates for President in 2016 is whether they would have supported the war in Iraq. A common theme is that if we knew then what we know now, the decision would have been different. But here is the problem: Even if what we thought we knew then turned out to be true, the war was still a bad idea and should not have been fought.
Hindsight is always 20/20, and we may not know the real impact of the Iraq war for a generation. This is because the effects of that war are still forming and will be for at least the next few years. What we see in ten or twenty years may be completely different from what we see today. But if we're really interested in avoiding the mistakes of the Iraq war, we need to challenge the assumptions we (and I do mean we, because I was a supporter of the war from 2003 to 2008) made that led us into this armed conflict and "regime change."
The first faulty assumption is that we are supposed to be the world's policeman and that we should project American military power to restrain, punish or eliminate bad actors from the world stage. President Obama made the exact same assumptions when he used military force in 2011 to force "regime change" in Libya that President Bush made in 2002 and 2003. (Assumptions that were supported by Hillary Clinton.) That does not make us a nation or even a leader among nations - that makes us an empire. We should not be an empire.
The second faulty assumption is that Saddam Hussein could not be contained. We have dealt with evil regimes with weapons of mass destruction for generations, going back to the Soviet Union after World War II. We have never seen our enemies use WMD against us because they know the consequences of doing so would be too horrible to contemplate. Even if Saddam had or was seeking WMD (including nuclear weapons) he was not stupid enough to use them and bring the nuclear wrath of these United States down upon him.
What we should do is embrace nonaggression as the cornerstone of our foreign policy. War should only be used in the case of a direct attack on our national security interests, and even then it should always be the last resort. We had to go to war with Japan and Afghanistan, for example, because those nations directly attacked us at Pearl Harbor and in New York City. Iraq represented no such threat. Our war in Iraq was a preemptive war to stop a possible threat in the future, and now we are dealing with the consequences of that decision.
If we want to repeat the mistakes of Iraq, looking at it through the lens of hindsight will never accomplish that goal. Only by completely changing our perspective, our assumptions and our basic foreign policy strategery can we avoid making that same mistake again.