When I received my Post e-mail alert about the bombing in Norway, my first thought was that it was al-Qaeda. That was reinforced when the second alert came about the youth-camp shootings. Near-simultaneous attacks are a hallmark of al-Qaeda-inspired terrorism. Many analysts and news organizations speculated similarly in the hours after the Norway attacks.

So what explains the vociferous and voluminous amounts of e-mail I received last week denouncing Post opinion blogger Jennifer Rubin for making similar points online immediately after the bombing?

Several factors are at work, including Rubin’s role at The Post, her style, her faith, how the liberal and conservative blogospheres work on the news cycle, and, finally, a certain American insensitivity toward mass casualties in other lands.

First, the insensitivity. Remember the days after the attacks of Sept. 11, 2001, when most of the world stood still for us, gripped by shock and tearful with sympathy for New York and Washington? For weeks the world offered prayers, assistance, mourning and solidarity with the United States.

But when an attack happens elsewhere, whether Oslo, Bali, Madrid, Beslan, Mumbai or London, U.S. pundits and politicians climb on their electronic soapboxes and denounce the act as one more evil deed by the enemy we most love to hate, be it militant Muslims, or in Oslo’s case, militant Christians. There is no interval before scoring rhetorical and partisan points, not even time to mourn.

Rubin fell into this trap. She cited terrorist expert Thomas Joscelyn’s speculation that it had all the hallmarks of an al-Qaeda operation, and then she argued that we don’t dare cut defense or homeland security funding, even in a debt crisis, because jihadists are still after us and we live in a “very dangerous world.”

What compounded Rubin’s error is that she let her 5 p.m. Friday post remain uncorrected for more than 24 hours. She wrote four other unrelated blog posts that night, through about 9 p.m. Police officials in Norway at 8:33 p.m. Washington time had made their first statement that the suspect had no connection to international terrorism or Muslims. Rubin should have rechecked the facts before signing off, and Post editors should have thought about editing her post more that night.

But Rubin has a good defense. She is Jewish. She generally observes the Sabbath from sundown Friday until sundown Saturday; she doesn’t blog, doesn’t tweet, doesn’t respond to reader e-mails.

When she went online at 8 p.m. Saturday, her mea culpa post on Norway was the first thing she posted, although its tone also hurt her, particularly this sentence, which struck many readers as borderline racist: “There are many more jihadists than blond Norwegians out to kill Americans, and we should keep our eye on the systemic and far more potent threats that stem from an ideological war with the West.”

There are other reasons I got so many e-mails on Rubin; they have much less to do with terrorism and tragedy and more to do with modern technology and partisan politics.

Liberals and conservatives don’t talk to each other much anymore; they exist in parallel online universes, only crossing over to grab some explosive anti-matter from the other side to stoke the rage in their own blogosphere.

The liberal blogosphere, propelled by tweets, picked up Rubin’s piece and spread it around rapidly, helped by a trifecta of posts from theatlantic.com.

If your politics are liberal and you don’t generally read Rubin, but you read her Norway posts, you probably would be pretty offended. But if you are a conservative, or someone who reads Rubin regularly, you’ll know that this is what she does and who she is.

Rubin was hired by Fred Hiatt, editorial page editor of The Post, to be an opinion blogger who would appeal to conservatives and people who want to follow conservative politics. She does.

She is the most prolific opinion blogger at The Post, doing eight or 10 posts a day often, most of it insider stuff on GOP politics, a lot of it based on single sources. But Rubin also gets scoops. She has excellent sources in the House and Senate leadership, and lots of Republicans read her and trust her.

In a long chat with Rubin last week, I found her forceful and unrepentant, yet not unreasonable. She is not an ogre or a racist. And she does not deserve some of the calumny she got. Some of the e-mail she received was way over the line — ugly, obscene, vile and, worst, containing threats of physical harm.

This brings us back to the shootings in Norway, an act committed by a disturbed man who drew some of his inspiration from extremist Web sites. A blogosphere given to vitriol and hasty judgments ought to consider the possible consequences of its own online attacks.

Patrick B. Pexton can be reached at 202-334-7582 or at ombudsman@washpost.com. For updates, read the omblog at washingtonpost. com/ombudsman-blog/.