When the PBS NewsHour covered John Kerry’s dramatic presentation on the alleged chemical weapons attack in Syria on August 21, reporter Jeffrey Brown (8/30/13) zeroed in on the death toll:

KERRY: The United States government now knows that at least 1,429 Syrians were killed in this attack, including at least 426 children. BROWN: The chilling numbers stood out from the U.S. intelligence assessment released this afternoon. And, lest anyone doubt, the secretary of State insisted, its findings are as clear as they are compelling.

On ABC World News (8/30/13), Martha Raddatz emphasized the numbers as well:

It is the images and the stories from the survivors that are clearly the most compelling. And that number 1,429–1,429 killed, including those 426 children.

On NBC Nightly News (8/30/13), anchor Lester Holt said that Kerry had “revealed that more than 1,400 people had been killed in the chemical attack, including more than 400 children.” Note: “revealed,” not “said” or “claimed” or “alleged.”

And the New York Times editorial page (8/31/13), in a piece about the need for stronger legal justification for launching an attack on Syria, wrote definitively that such action would be “in response to a chemical weapons attack in Syria that killed more than 1,400 people.”

But where does that number come from–and why is substantially higher than other estimates? As the AP (8/31/13) reported:

But the Syrian Observatory for Human Rights, an organization that monitors casualties in the country, said it has confirmed 502 deaths, nearly 1,000 fewer than the American intelligence assessment claimed. Rami Abdel-Rahman, the head of the organization, said he was not contacted by U.S. officials about his efforts to collect information about the death toll. “America works only with one part of the opposition that is deep in propaganda,” he said, and urged the Obama administration to release the information its estimate is based on.

And Hannah Allam and Mark Seibel of the McClatchy news service (9/2/13) noted that substantially lower death tolls were released by Britain (more than 350) and France (281).

Much of the case the U.S. is making against Syria is based on intelligence that the government is so far unwilling to make public (Washington Post, 9/2/13)–and some of what is available is not terribly convincing (Truthout.org, 9/3/13).

So journalists should, at a minimum, attribute these estimates to the government–and note that they are not in line with other reputable estimates of the death toll in Syria. Ideally, reporters should ask John Kerry to explain the discrepancy. He just made the rounds on all the major Sunday chat shows, and no one who was interviewing him thought to bring it up.