Brummett watched the news replaying the explosion over and over. "When C4 explodes it has a crack. It doesn't sound like anything else." The bombs in Boston didn't sound like that. This was more "gunpowderish," Brummett says. (The Washington Post reported Tuesday night that some investigators think black gunpowder might have been used because the blasts were not strong enough to cause structural damage to buildings or gouge the sidewalk.) "Probably had a timer," he said. (An official told The New York Times an egg timer was used.) Nick Cox, a former Army specialist who deployed to Iraq twice, saw the white smoke and figured it was the work of an "amateur." (Wired reports the white smoke indicates the explosive was gunpowder.) Of the bomb made of a pressure cooker, Staff Sgt. John Sellars thought, "Wow, that's some OIF-2 shit right there," referring to the military's term for the second year of combat operations in Iraq. "Ball-bearing IEDs would do a number on the old-school Humvees," Sellars said. "Then we started up-armoring everything… so that generation of IED wasn't any good anymore." In Iraq, the American armor and insurgents' weapons were constantly evolving. That hasn't happened in America, of course.

"It was a little weird, actually," said David Warnock, a former sergeant who went to Iraq twice and whose sister lives in Boston. He's now going to school at Ohio State. On Monday afternoon, "I was just doing some restorative yoga. So I was like, really mellow when I got out, and I had a series of text messages asking about my sister without any context."

"I went through some weird stages," Warnock said. "At first, just, like, shock and anger -- how could this happen here? Then I guess I realized I'm sort of surprised it doesn't happen more. Then I was like, I just read on the BBC there was another wave of bombings in Iraq that killed like 40 civilians. And I paused to reflect on the paradoxical situation that I would be so shocked and outraged over what happened in a city that my sister lived in but not a country I once tried to help."

The news "instantly" brought back memories of Iraq, Brummett says. "I've been walking around all day thinking about it… It's not even so much an American thing. It's a human thing... Because I was there. It wasn't any less dramatic to me, watching it happen to another race of people than it was to see it happen to white people in America… It's not an American thing. It's terrible this happens anywhere in the world."

That's what bothered Sellars, now stationed in Fort Hood, Texas, about the media frenzy after the marathon bombing. "Every time something like this happens, I find myself angry," Sellars said. "Not that someone would do that on American soil, but that Americans react the way they do… Because we have this attitude that that can't happen here -- bombings are something that happens in Third World shitholes." (Or as Politico quoted Tom Brokaw on Tuesday: "We're the most advanced nation in the world, living with Third World vulnerabilities.") This bombing was so small compared to some things he saw in Iraq. The bombing in Boston, while awful, "is nothing like six artillery shells in the back of a car," Sellars said, referring to an IED set off in front of a mosque after Friday prayers in 2007. That was "carnage." He saw a photo of the 78-year-old marathon runner getting knocked down by the blast. He felt for the guy, but, "He should count himself as fortunate."