First ask yourself - which story would you read first?
I don't imagine it's that New Zealanders place more value on an American life than, say, an Iraqi life, but that a story about a rare bomb attack at a major sporting event in the United States - an event Kiwis are involved in - is more likely to engage readers and viewers than another story about mass killings in Iraq.
That's not to say we shouldn't care about what's happening in Iraq, but counting bodies to prove a point is obscene - it's not a competition.
It's disturbing that deaths like those in Boston are seized upon by critics as opportunities for political point-scoring.