Even though he became one of America's most influential defense secretaries, Robert Gates really, really wanted to retire this year. It was a punch-line in his jokes. He had started saying his goodbyes months ago.
President Barack Obama's decision to name a new defense secretary answers Gates' wish, but the hole he leaves will be difficult for anyone to fill -- even his seasoned replacement, 72-year-old CIA director Leon Panetta.
Recruited by President George W. Bush in 2006 at the height of the Iraq war, the soft-spoken Gates changed the tone at the Pentagon, offering a less-combative style than his predecessor Donald Rumsfeld but having no qualms about firing top brass who failed to deliver.
Obama took the unprecedented step of asking Gates to stay on shortly after winning the 2008 presidential election, a potentially risky move that instead saw the self-described -- but not registered -- Republican become one of the strongest voices on Obama's team.
As the first defense chief to straddle Republican and Democratic presidencies, Gates lent Obama greater credibility in Congress on issues of U.S. security. That was no small task given Obama's inexperience in military affairs and opposition to the Iraq war.
One of the longest-serving defense chiefs in U.S. history, Gates' influence was apparent during Obama's review in 2009 of Afghan war policy that ended with a decision to send 30,000 additional troops.
Known for his candor, Gates, 67, in his final months on the job played down the likelihood of another Iraq- or Afghanistan-style conflict in the future, saying the U.S. military needed to adjust to an era of light, nimble warfare.
He bluntly told cadets at the West Point military academy in February that any future defense secretary who advised the president to again send a big American land army into Asia, the Middle East or Africa should "have his head examined."
More recently, he was a voice of caution about the limits of U.S. action in Libya beyond air strikes, fearing mission creep that could drag America deeper into a third conflict after nearly a decade of constant war.
While U.S. war policy is not expected to greatly change with his departure, the future of military spending is not as clear. Gates was a strong opponent of deep cuts in military spending. but Obama has publicly announced plans to slash $400 billion in security outlays by 2023.
Gates led his own cost-cutting drive but also warned that significant further reductions would mean forgoing military missions or cutting back troops.
"My greatest fear is that in economic tough times that people will see the defense budget as the place to solve the nation's deficit problems," he told reporters last August.
The White House hopes to get Panetta confirmed by the Senate in time so that Gates can retire on June 30. After that, Gates plans to write books, give speeches and spend time with family and friends back home in the Pacific Northwest, said Pentagon Press Secretary Geoff Morrell.
SIMPLER DURING THE COLD WAR?
Gates, a former CIA director whose career was largely built within the spy agency during the Cold War, has an unflappable style and rarely shows emotion -- except on occasion when addressing troops. In rare moments, his eyes tear up.
As defense secretary, he ramped up funding for armored vehicles that better shielded troops from roadside bombs -- insurgents' weapon of choice to kill and maim U.S. forces in Iraq and Afghanistan.
Nearly 4,450 U.S. soldiers have been killed in Iraq since that war began in 2003 and more than 1,500 have died in Afghanistan.
Hardly rosy in his world view, Gates watched with apprehension as unrest began sweeping the Middle East and Africa this year -- fast-moving, historic events whose outcome he conceded were difficult to predict.
"In the days of the Cold War it seemed to me the world was a lot simpler," Gates said, almost nostalgically, during a recent trip to St. Petersburg, Russia.
"There was the Soviet Union and there was us and almost every problem in the world was defined by that relationship."
When WikiLeaks published secret State Department cables last year, sparking fears for the future of U.S. diplomacy, Gates predicted fallout would be modest.
"The fact is governments deal with the United States because it is in their interests, not because they like us, not because they trust us, and not because they believe we can keep secrets," he said.
Gates has sometimes lashed out at the Pentagon bureaucracy, accusing some military officers and defense industry executives of "next-war-itis" for fixating on possible future conflicts with nation-states instead of concentrating on irregular warfare in Iraq and Afghanistan.
He was also quick to hold Pentagon officials to task.
Even in the Bush administration, widely criticized for not holding people accountable for failure, Gates fired the Army's top civilian in 2007 due to a scandal over the treatment of wounded troops.
In 2008, he took the unprecedented step of sacking the top uniformed and civilian officials in the Air Force over nuclear-related blunders.
The past two commanders in Afghanistan were also fired under his watch, including General Stanley McChrystal, who was sacked because of a profile in Rolling Stone magazine last year seen as disparaging the Obama administration.