When some of our friends in academia read the top news about Syria on a website or in a newspaper, they do so through a lens ground by UCLA political scientist John Zaller. In a 2003 paper (pdf), Zaller analyzed two modes of news production that journalists often employ. While working in patrol mode, the press surveys the landscape for trouble and writes up what it finds, like a cop walking a beat and writing the occasional ticket or making the routine arrest. In alarm mode, aroused reporters respond to calls for help by lighting up the gumball, tossing it on the roof, and peeling out for the crime scene, the building afire, or the battleground.

I simplify Zaller here, just as he modified the patrol/alarm idea of two other political scientists on his way to his insight. But the simplification stands: The journalistic transmission knows two basic gears: slow or fast; monitoring from afar or fully entrenched; casual or obsessed. The press has long treated Syria as just another stop on its Middle East patrol, even though it has regarded massacres as legitimate tools of governance for decades, as this BBC timeline indicates. The migration of the two-year-old Syrian civil war from the back pages to the front, where it now amasses acres of newspaper coverage, can be attributed in equal part to the chemical attacks of late August in the western suburbs of Damascus and the puncturing of the Muslim Brotherhood government in Egypt. There’s nothing like chemical weapons dumped on innocents followed by a U.S. president’s threat to drop bombs to change the location of the loudest alarm.

I’m not disparaging anything that’s alarmed-based, just acknowledging that it best describes contemporary news coverage, a sentiment shared by many of the scholars cited in a new book by University of California, Davis, political scientist Amber E. Boydstun, Making the News: Politics, The Media, and Agenda Setting. Boydstun argues that in practice, the press follows neither the alarm model nor the patrol model, but oscillates between the two. “[N]ews outlets tend to only patrol those neighborhoods covered by beats or triggered by alarms,” she writes. Woodward and Bernstein responded to a minor alarm story, went into patrol mode, and as other news organizations followed, the patrol coverage escalated to alarm mode again and again.

Explosive events drive day-to-day coverage, she writes, but that’s not always the case. She offers the Boston Globe‘s enterprise treatment of the Catholic priest sexual-abuse scandal as an example of a news organization that sounded an alarm rather than responding to one. Such alerts, as often as not, signal to the press the need to add a neighborhood to its patrol list.

Although the Syrian body count did not spike with Damascus gassing, the alarm it sounded refreshed all news generated by the region. Beyond who gave the order to fire the weapons and how many the gas bombs actually killed, the attack rang journalistic alarms on the White House beat, because the president is threatening retaliation; on the Pentagon beat, because the general and admirals are fiddling with battle plans; and on the diplomacy beat, because every ambassador and foreign secretary with portfolio is working to prevent the worsening of this vile civil war.