It was a great moment of national pride for me (which are rare in the UK) in the wake of the 7/7/2005 bombings. People were back on the Tube and buses the next day, refusing to allow their lives to be disrupted further. I've always taken solace from those people- I hope that the people of Boston can be equally inspiring.
We here tend to work more of a spirit of freak-outery and cynicism. And as much as it annoys me, I think its more a symptom of how relatively little most of us and our ancestors have had to worry about in the US as much of our history was as a mostly rural international backwater that quickly transitioned quickly to a world power with oceans and, almost always, peaceful neighbors on its borders.
Which is something to be thankful for, even if it has led to a fairly weak resolve.