WASHINGTON When President Barack Obama launched the Libya campaign over the objections of top commanders, it was seen as a sign of how far his White House had drifted from the Pentagon just across the Potomac River.
But Obama's decision to intervene in Libya, where Muammar Gaddafi remains defiant after a week of coalition air strikes, more accurately underscores the limits of Pentagon influence in any White House, along with the mutual skepticism that runs deep between U.S. civilian and military leaders.
Tensions have run high at times between commanders and Obama, a Democrat whose opposition to the Iraq war helped him win his party's nomination to run for president.
As Obama assessed his options for the Afghanistan war in 2009, the White House bristled at what it saw as pressure from the military for a big troop increase. In the end, he sent 30,000 extra troops, but set a firm deadline for initiating withdrawal.
Some of the wariness remains, but it's not an unusual situation between the military and many presidents, including George W. Bush and Bill Clinton.
"I don't think there has been any White House where the Pentagon has been able to dictate everything it wants," said Max Boot, a senior fellow at the Council on Foreign Relations.
"Today there was very little enthusiasm on the part of senior officials and Defense Secretary Gates to intervene in Libya. That was overruled ... and I think that's a very proper thing. Obama is the commander in chief."
Obama, who has not served in the military, tried early on to ease fears in the Pentagon that he would not heed expert military advice as he pressed for conclusions to the long, costly wars in Iraq and Afghanistan.
Hoping to build a solid relationship from the start, Obama kept Robert Gates, a Republican holdover, as defense secretary and picked veteran Marine commander General James Jones as his first national security adviser.
Still, ties with the White House suffered from a leaked 2009 memo by General Stanley McChrystal, then commander in Afghanistan, that put pressure on Obama to approve the troop surge by arguing the war could be lost without a bigger force.
In the end, Obama granted McChrystal most of the additional troops he sought but the lingering tensions were laid bare in an article in Rolling Stone magazine that resulted in McChrystal's dismissal last year.
Obama could not have been pleased by comments from McChrystal advisers in the article that painted the president as intimidated at an early meeting with the general.
Administration officials say Obama has a solid working relationship with McChrystal's successor, General David Petraeus, who is mentioned as a possible presidential candidate in 2012 or 2016. But they are not particularly close.
Bush, by contrast, forged a close bond with Petraeus, who helped to sell the Republican president's Iraq troop buildup to a skeptical U.S. Congress.
David Rothkopf, a former Clinton administration official who has written a book about the National Security Council, said the military's ties with Obama's core security advisers at the White House were at times rocky.
"It's clear that it's a functioning relationship and in terms of meetings, it's even a respectful relationship -- but underlying it is a lot of tension," Rothkopf said.
Much of the speculation about a divide over Libya was fueled by Gates, who voiced concerns about the risks of a campaign that could bind the United States to another war.
"Let's just call a spade a spade. A no-fly zone begins with an attack on Libya," Gates told Congress in comments that were seen as delaying the Obama administration's decision to push for the U.N. resolution that authorized the Libya campaign.
But a senior White House official said concerns aired publicly by Gates and Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, were initially shared by Obama.
"I think people here feel that those were good points to make," the official said on condition of anonymity. "Gates never said we shouldn't do this. He simply said that a no-fly zone is not a cost-free or risk-free proposition."
The official, who attended an Oval Office meeting on Libya Friday, said there was no evidence of friction among Obama, Gates, Secretary of State Hillary Clinton and others present.
One defense official noted that Obama's style, in which he encourages vigorous policy debates at the most senior levels, might foster the appearance of civilian-military divisions.
Bush, on the other hand, wanted everyone on the same page by the time the meeting was over.
But Bush also clashed with the military. Some of his top brass did not favor a troop increase for Iraq, prompting him to promote Petraeus, a strong supporter of the plan. Bush also presided over a contentious move to restructure the military.
Clinton began his first term at odds with the Pentagon over his position on homosexuals in the military and was dogged by criticism about his own lack of military service.
Military officials said the perspectives of the Pentagon and White House were bound to differ.
Analysts said the bottom line, as seen in Libya, is that even when military grumbling occurs, the Defense Department is a machine built to obey the chain of command.
"It's not unusual for the president to give orders that the military might not entirely agree with but they carry them out," said Mark Quarterman at the Center for Strategic and International Studies. "Once they're given orders, they follow those orders."
(Additional reporting by Steve Holland; Editing by John O'Callaghan and Doina Chiacu)