What a time for a chest cold.

With both his broadcast competitors in South Asia covering the tsunami disaster, ABC’s Peter Jennings is home in New York, nursing “a severe upper respiratory infection,” an ABC rep says.

Under doctor’s orders, Jennings cannot travel to the region, the rep says, but he’s well enough to anchor “ABC World News Tonight.” (The network’s big gun: “Good Morning America’s” Diane Sawyer, is in Thailand.)

Dan Rather of “CBS Evening News”‘ and Brian Williams of “NBC Nightly News” were both to begin co-anchoring Monday night from the region – Rather from Bangkok, Thailand, and Williams from Banda Aceh, ground zero in Indonesia.

With the tragedy in its second week, and with an estimated 150,000 deaths, why did the networks wait so long to dispatch their A-teams?

“The first thing we do is get our correspondents to the scene,” says CBS’s Marcy McGinnis, senior vice president, news coverage.

Sending an anchor “involves debate,” she adds. “You have to decide whether you’ll get a bang for your buck. Where can he go? What can he get? You can’t always get that kind of satellite time.”

“60 Minutes” Wednesday made the decision when it arranged for Rather to get aboard the USS Abraham Lincoln, en route to Indonesia with food and supplies.

Piggybacking on the assignment, CBS asked Rather to also coanchor for “Evening News.” (As if he had to be asked.) His “60 Minutes” piece airs Wednesday at 8 p.m. EST; he will join the newsmagazine full-time after he steps down as anchor March 9.

NBC kept Williams in New York last week “because I didn’t want him to miss a night on the air,” says “Nightly News executive producer Steve Capus.

“He was on the job all last week when seemingly the rest of the world was on vacation. As everybody else rang in the New Year, Brian traveled 46 hours to get into the hardest-hit area of the hardest-hit region.”

It’s the first big story for Williams since succeeding anchor Tom Brokaw Dec. 1. Ditto for CNN/U.S. president Jonathan Klein, named to the post Nov. 22.

CNN has about 75 staffers on the ground in the region – about 25 more than any of the broadcast networks. The cable channel dispatched 50 troops from its bureaus around the world “immediately” after the story broke Dec. 26, Klein says.

The anchors begin reporting this week: Anderson Cooper of “Anderson Cooper 360” from Sri Lanka, “NewsNight’s” Aaron Brown from Indonesia, and “American Morning’s” Soledad O’Brien from Thailand.

“Unlike our domestic competitors, we didn’t need to scramble to send our domestic people over,” says Klein, a CBS alum. “Because we are based in so many places around the world, this was our “quick reaction’ team.

“When we focus on a story, there’s no bigger footprint in the world.”

As the disaster’s aftermath stretches into its second week, “we want to bring a new dimension to the storytelling,” Klein says. “We’re upping the ante by sending more troops to the scene.”

Over at Fox News Channel, several anchors have volunteered to go on-site, but the network is “happy, delighted, extremely impressed” with its team of almost 30 field reporters and producers, says Kevin Magee, vice president, programming.

“At this point, it’s a wildly disparate story. Our anchors can probably do a better job of pulling together and disseminating information in New York than they can standing on a beach over there.”

All the networks agree on two points: Working conditions in the region are horrifically difficult, and there are no hard and fast guidelines for broadcasting graphic images.

“When you see it, you know whether it’s too horrible to show,” says CBS’s McGinnis.

Says FNC’s Magee: “When images are used to shock instead of inform, you’re going overboard.”

For CNN’s Klein, the barometer is simple: “Will it give my 4-year-old son nightmares?”