It has been quite a week for Barack Obama. The US president has managed to force through a new nuclear arms reduction treaty with Russia and a repeal of the controversial "don't ask, don't tell" policy before the new Republican-majority Congress takes over in January. He owes those victories, in large part, to Admiral Mike Mullen.
Nowhere was this more true than the repeal of the decade-old policy of requiring homosexual members to lie about their sexual orientation to serve in the military.
One line of Adml Mullen's testimony to the US Senate's armed services committee has been quoted more than any other: "I cannot escape being troubled by the fact that we have in place a policy which forces young men and women to lie about who they are in order to defend their fellow citizens. For me personally, it comes down to integrity - theirs as individuals and ours as an institution." Mr Obama made a point of reiterating these remarks before signing the repeal.
Cynics might say this is nothing more than the company line. Certainly, Republican senators made insinuations and, at times, open accusations that Adml Mullen put the wishes of the US president over those of the troops under his command. That, however, does not fit the profile of Adml Mullen. He is a fact-driven mathematical mind who arrives at his own conclusions.
As one of the last veterans of the Vietnam War in active duty, Adml Mullen has often been invited to draw comparisons between that conflict and those in Iraq and Afghanistan. One comparison never drawn, however, is between a fellow mathematics genius, the Vietnam-era secretary of defence and former Ford Motor Co "whiz kid", Robert McNamara.
Given McNamara's troubled legacy, the comparison is not charitable, but both men applied their keen analytical minds to their jobs. Both have been said to think more like machines than men.
Like McNamara, Adml Mullen has been equally accused and praised for running the military as a CEO, and his business acumen has led him to be profiled by several business publications. However, Adml Mullen has a soft side and a respect for "integrity" that is rarely attributed to the "IBM machine with legs", as Barry Goldwater once called McNamara.
Within the military, he does not fit the typical profile of an inspirational leader. He is not a "hard charger" like his predecessor Gen Peter Pace, of the US Marine Corps, who was a favourite among the troops for his brusque manner and religious piety. Nor is Adml Mullen a "scholar-warrior" like Gen David Petraeus, although he was once mistaken for the man credited for saving the war in Iraq.
As the keynote speaker at a charity event last year, he was expected to keep the speech light and humorous. Humour does not seem to come easily to Adml Mullen. During an appearance on The Daily Show, the only laugh Jon Stewart was able to elicit was when he asked whether the admiral would like him to shut up.
With the spotlight now on him, Adml Mullen chose to tell the assembled crowd how he once told a woman that he was the president's "top military adviser", to which she replied: "Oh my goodness. General Petraeus, I did not recognise you."
Michael Glenn Mullen was born in Los Angeles in 1946. The son of a Hollywood press agent to stars such as Julie Andrews and funnyman Jimmy Durante, Adml Mullen retains a love for the bright lights of show business. Guests at the regular dinner parties he hosts on the naval compound in Washington note that the walls are adorned with Broadway playbills. Growing up, Adml Mullen harboured no particular desire to join the military.
He attended the US Naval Academy on a basketball scholarship, because he needed money. His family was reportedly surprised to find how quickly he embraced the regimented lifestyle of its students. During his final year, the mathematics and engineering major met his future wife, Deborah, through a mutual acquaintance at a wedding they both attended.
Despite his love of the naval academy, he had no intentions of making a career out of military service. "I only expected we would be in the navy about five years," Mrs Mullen said on their 40th wedding anniversary this year.
In 1968, upon graduation, the young ensign was sent to serve in Vietnam. Two years later, he and Deborah were married.
A young Lt Mullen got his first command in 1973, the fuel tanker USS Noxubee. He provided fuel support to the Sixth Fleet as it patrolled the eastern Atlantic and the Mediterranean.
After 15 years in the navy and a stint as an administrator back at his alma mater, then-Commander Mullen contemplated returning to school for a master's in operations research at the naval post-graduate school in Monterrey, California.
Operations research was invented in the UK around the time of the Second World War. It applies mathematical modelling and statistical analysis to shape the way organisations such as the military do business. These sorts of eggheaded analysts and their obsession with "bomb-cluster photos" were parodied in Joseph Heller's classic novel Catch-22, but Adml Mullen's natural aptitude for maths attracted him to the concept.
The superior officer advising him said going back to school this late would end his career. He wanted him to back at sea. The attrition rate for officers increases exponentially for every rank above commander - the more experience an officer has in commanding a ship, the better his chance of promotion. "He didn't quite have that right," Adml Mullen said in an interview in July.
Adml Mullen also wanted to go back to school to spend more time with his two sons, Michael and John, in his native state of California. "I had two little kids, [my wife and I] were both from California. There was a family side of this, which was an important part of all of our careers."
Today, Adml Mullen credits his degree for much of his success. The mathematical methods of his thinking taught him to "frame a problem" to "bound it and ask hard questions that will push the system in the direction of an answer". It was his analytical skills that propelled him through the ranks of the service, where he worked on new technology for a next-generation navy.
In 2005, Adml Mullen became the chief of naval operations, the highest-ranking naval officer. At the time, the US navy was undergoing something of an identity crisis and its relevance was being questioned. It had little or nothing to do with the wars in Iraq and Afghanistan. He was determined to change this.
Adml Mullen directed a research project that led to the publication of a new maritime strategy, the first in 20 years. Titled "A Co-operative Strategy for 21st Century Seapower", the work caught the eye of the new US secretary of defence, Robert Gates.
One of Mr Gates's ambitions as the Pentagon chief has been to trim the fat from what he sees as a bloated military designed to fight yesterday's wars. He has sought to cut funding to defence research projects and next-generation military equipment and he found a willing ally in Adml Mullen. This alliance has helped Adml Mullen survive a change in administration.
Prominent victims of the Gates-Mullen partnership have been the air force's darling, the F-22 fighter plane and the army's future combat system. However, Adml Mullen has been keen to save certain programmes and calculate how much of this new technology the military really needs. Although orders for the F-22 have been cut to 183 from 750, projects such as the littoral combat ship, relatively small vessels designed to operate close to shore, have been rescued from the dustbin.
He remains as much focused on the future as in the 1990s when he worked on building many of the projects now facing cancellation. During his first press conference after becoming the chairman of the joint chiefs, Adml Mullen warned that the focus on counterinsurgency and fighting the current wars mean that troops "haven't been training in or focusing on this wider spectrum of requirements should we need to be called to do something else".
Gen Petraeus has been credited for the popularity of counterinsurgency among military pundits as well as reviving the basics of fighting a war. His influence has led these pundits to dust off their copies Carl von Clausewitz's seminal treatise, On War. The thrust of mainstream military thinking today is very much on what can be done and the realities of warfare.
Adml Mullen, meanwhile, is the far-sighted pragmatist making sure the future is not lost in the rush to embrace the principles of the past - to ensure that what needs to be done is not lost by concentrating on what can be done.
What made Adml Mullen's testimony before Congress so compelling was not its emotional content. It was its logic - he "bounded" an emotional problem.
How do you get Republicans to repeal a ban on homosexuality, when their political support comes from a base of people largely opposed to same-sex relationships? You frame it in terms of "integrity", which Republican legislators hold as a hallmark of their political identity.
What makes Adml Mullen different, however, is his own personal integrity - that he is, after all, more man than machine.
Born October 4, 1946, Los Angeles
Education US Naval Academy (bachelor’s), Naval Postgraduate School (master’s)
Service US navy since 1968
Wars fought Vietnam War
Selection of commands held Chairman of the Joint Chiefs of Staff; chief of naval operations; US naval forces Europe; US Second Fleet; USS Noxubee
Awards Defense Distinguished Service Medal, Navy Distinguished Service Medal, Defense Superior Service Medal, Legion of Merit, Global War on Terrorism Service Medal
Three principles about the “proper use of modern military forces” Military power should not be the last resort of the state; force should be applied in a precise and principled way; policy and strategy should constantly engage with one another