Even as the investigation into the Boston Marathon bombing is revealing details about the bombers, a recurring reaction has been to insist that their motives don't matter. After all, who cares why people engage in acts of terrorism that kill innocents and children? It's not possible to explain why, because it's simply evil or insane.
Rush Limbaugh has voiced this position repeatedly, adding that the "quest for why" is an attempt to "find a way to blame America." People on the left asking, "Why do they hate us?", Limbaugh says, are looking for a way to justify the bombing because, he says, "they don't like this country, either."
In part, this is name-calling and caricature. But it's also a serious misunderstanding of why we investigate crimes and terrorism, because explaining such things can give us valuable knowledge.
First, a conceptual distinction: explaining why someone does something is different from justifying it. We can explain why Hitler hated Jews and instigated the Holocaust: he believed Jews were a threat to the German race. For instance, he believed the stab-in-the-back myth that Jews caused Germany to lose World War I. Whatever details we cite, though, at no point are we justifying or accepting his behavior. So, trying to explain what Dzhokhar and Tamerlan Tsarnaev did doesn't logically commit you to defending the Boston Marathon bombings.
And we should investigate the motives of people like the Tsarnaevs, because figuring out the motives behind terrorist acts can be key to undermining terrorists.
An illustration of this comes from Anbar province in Iraq. Sunnis in Anbar were horrified after the US overthrow of Saddam Hussein brought a Shiite government to power. Anbar became a haven for Al-Qaeda in Iraq (AQI) and the Islamic State of Iraq (ISI), Islamic caliphate supporters that carried out any number of deadly terror attacks on civilians, and frequently killed US and coalition troops.
But then the Anbar Awakening (AKA the Sons of Iraq, Concerned Local Citizens, the Sahwa) happened. Sunni militants — people who had fought US forces or even fought alongside AQI — turned against the terrorists. In September 2006, they united under a fellow sheikh, Abdul Sattar Abu Risha, and the situation in Anbar changed almost magically. Violence dropped in half.
But, whatever the motives of these militants, they did switch sides, resulting in a victory for the US and a loss for Islamic terrorists. They stopped giving material support to AQI, they shared vital intelligence with the US, they even engaged AQI in combat. Sometimes money made the difference: the US paid Awakening members $10 a day, a tempting offer in war-torn Anbar. But the difference was to our advantage and to AQI's detriment.
The moral of the story is this: terrorists can sometimes be turned. Some Awakening members had fought and killed US troops or helped AQI kill civilians. Siding with them — much like our alliance with Stalin against Hitler — was distasteful at best. But it probably saved more innocents and U.S. soldiers in the long run, because it led to the defeat of the hard-core members of AQI.
Just prior to the Awakening, AQI leader Abu Musab al-Zarqawi was killed thanks to intel gained from one of Zarqawi's own associates, who had been captured and interrogated by the US. Matthew Alexander — a pseudonym for one of the US interrogators — found that "many disgruntled Sunnis could be peeled away from Zarqawi" because many of them weren't like Zarqawi. They had different motivations, sometimes stemming from misconceptions about the U.S. (they saw the Abu Ghraib abuses as typical U.S. behavior, not aberrant).
Which brings us back to the Boston Marathon Bombing. Terrorism is morally wrong and terrorists are bad people. We should kill them when we can. But they're not all Zarqawis. And understanding that difference can get some people to switch sides and help us stop terrorists. That's not "blaming America," that's achieving our goal: less terrorism.