Nowhere was the difference between the cable news networks on starker display than in prime-time coverage on the night the last American combat brigade left Iraq following a war that started seven years and five months ago.

MSNBC devoted its entire prime-time footprint to the story, with Richard Engel riding with the troops in a specially equipped vehicle and host Rachel Maddow based in Baghdad. Keith Olbermann anchored the coverage from a New York studio.

Fox News Channel devoted just under 10 minutes to the story, much of it during Shepard Smith's 7 p.m. newscast. The network spent 45 minutes discussing the potential construction of an Islamic cultural center near ground zero, while that story wasn't mentioned on MSNBC at all. CNN, meanwhile, spent an hour on each story.

The news decisions led critics of Fox and MSNBC to suggest politics was at play in the coverage decisions.

Engel had been embedded with the 4th Stryker Brigade, 2nd Infantry Division, the last combat brigade in Iraq. Since President Barack Obama had said combat units would leave by Aug. 31, Engel was closely tracking the exit time with an eye toward providing live coverage, said Phil Griffin, NBC News executive in charge of MSNBC.

It was a chance to bring Iraq coverage full circle for NBC News. Engel was riding in the vehicle designed to provide live coverage while moving, nicknamed the "Bloom-mobile" at NBC because the late correspondent David Bloom first rode it in 2003 when American troops entered Iraq, Griffin said.

The evening presented a logistical challenge in that MSNBC's individual prime-time programs prepared telecasts for use in case military plans forced a last-minute delay, he said.

Given the access, a decision to devote the entire evening to the story was a "no-brainer," Griffin said. "We've got something unique and it's an important story. We said, 'Let's go for it.'"

The Iraq story was important, one that had been given short shrift in the media in recent years, said Tim Graham, director of media analysis for the conservative Media Research Center. But with MSNBC's left-of-center opinion lineup, politics has to be considered part of the equation, he said.

"I would certainly think politics are involved in their 'flooding the zone' to suggest that 'Lookie here, the Obama people doing what they said they were going to do,'" he said.

Griffin said the access, technology and importance of the story drove the decision. "I don't think there was any politics in our coverage last night," he said. "It was about the soldiers."

White House correspondent Major Garrett and reporter Dominic Di-Natale in Iraq reported on the story Wednesday night for Fox. But during the opinionated Fox prime-time shows, the story clearly was given low priority. It was talked about for less than a minute total during news breaks in Sean Hannity's telecast. The "talking points" for Bill O'Reilly's top-rated show was about the Islamic cultural center, a single segment that stretched over eight minutes.

Ari Rabin-Havt of the liberal watchdog group Media Matters for America said he believed the Iraq story received little coverage on the opinionated shows because it did not reflect poorly on the president — unlike the Islamic center controversy.

"This was a big story about President Obama keeping one of his big campaign promises and it was virtually ignored," Rabin-Havt said. "It wasn't a campaign announcement. It was a conflict the nation has been embroiled in for seven years."

Fox representatives had no immediate comment on the criticism.

CNN's Rick Sanchez devoted much of his 8 p.m. EDT show to the Iraq story, while the bulk of "Larry King Live" concerned the New York City Islamic center and mosque. Anderson Cooper's 10 p.m. newscast split its time relatively evenly between the two issues.