During his recent visit to Afghanistan, Secretary of Defense Robert Gates told the troops it likely would be his last visit to the war zone as Secretary. Gates departure from Defense has been long anticipated, and there has been much speculation on whom President Obama will appoint to replace him. At the moment, CIA Director Leon Panetta appears to be the leading candidate, but is Panetta the best person to lead Defense given current circumstances, and if not, who is? What kind of person should replace Gates?

The United States is involved in wars in Iraq, Afghanistan, Libya, and against Islamist-Jihadist worldwide. China’s military power is rapidly expanding, threatening U.S. access and influence in the Asia-Pacific region. A nuclear armed North Korea is unpredictable. The Middle East is in turmoil. And Iran is determined to acquire nuclear weapons. Yet, President Obama is proposing cutting defense spending by $400 billion over the next ten years.

The person President Obama nominates and the Senate confirms as the next secretary of defense must lead and manage Defense, reducing fat without cutting muscle. Out-of-control deficit spending may require defense cuts, but not those that make us weaker and less secure. If this job isn’t done right, the next secretary of defense could preside over the beginning of the United States becoming a weakened military power.

There have been 22 secretaries of defense since the National Security Act of 1947 created the office. Having served under 14 of them during my 43-year military/DoD-civilian career, and eight of them during my 23 years in the office of the secretary of defense, including Bob Gates, I have an opinion on what qualities make a good one.

I won’t venture any opinions on which past secretaries I liked or didn’t like. Presidents don’t appoint secretaries of defense to win popularity contests, they appoint them to win our country’s wars and manage the enormous resources of the Department of Defense efficiently and cost effectively.

The best secretaries of defense, therefore, logically are those that not only are strong, decisive leaders with a firm grasp on world affairs able to guide wise presidential decision making, but those who understand and are skillful at managing defense procurement. The problem with the latter skill is that most acquisition decisions defense secretaries make during their time in office affect their successors more than themselves. The average tenure of a secretary of defense is 2.9 years. The acquisition cycle, from the time Congress funds a program until a major weapons system becomes operational, takes five to ten years or longer.

Few Americans can correlate the major weapons systems that are backbone of the United States armed forces' capabilities today with the secretaries of defense that championed and won funding for them. Acquisition programs for the F-22 Raptor date to the mid-1980s. For the M1 tank, they date to the 1970s.

Because defense procurement was such a major aspect of a defense secretary’s job, most of the early secretaries of defense came from industry or had acquisition experience in government. The first secretary of defense, James Forestall (1947-1949), had been the Undersecretary of the Navy during World War II where he effectively mobilized domestic industrial production for the war effort. Robert Lovett (1951-1953), was chairman of the board of the Union Pacific Railroad, the assistant secretary for air under the secretary of war overseeing the massive expansion of the Army Air Forces and the procurement of huge numbers of aircraft during World War II. Charles Wilson (1953-1957), was the president of General Motors (back when that meant something). Neil McElroy (1957-1959) ran Procter & Gamble.

More recently, however, most secretaries of defense have come from political backgrounds. Up until Acting Secretary William Howard Taft IV turned over the office to Dick Cheney in 1989, only Melvin Laird and Don Rumsfled, prior to his first appointment (1975-1977), had served in Congress. Of the last six secretaries over the past 22 years under four presidents, only Gates and William Perry (1994-1997) have not. Cheney and Rumsfeld also served as White House chiefs of staff.

This isn’t to say that people like Gates and Perry necessarily make better secretaries of defense, or that people like Dick Cheney, Les Aspin, Bill Cohen, and Don Rumsfeld are necessarily worse. It’s that they come to the office with vastly different perspectives that greatly influence their approach to the job. Given the unpredictable events that take place on their watch, they may or may not turn out to have been the right person for the job.

To the extent we can foresee the future at this point in time, however, we can make two predictions with a high level of confidence. The US armed forces will be stretched to deal with numerous wars and brush fires; and U.S. financial resources will be hard pressed to fund the necessary weapon systems and operational costs to meet those requirements.

If we are to navigate the dangerous economic and national security challenges ahead of us, we need a secretary of defense who has a firm grasp on the world around him, can lead a million-and-a-half unformed military personnel and manage the complex multi-billion dollar defense procurement enterprise. There are damn few people like that out there.

I believe Secretary Gates has done that about as well as anyone can. Whether or not Leon Panetta is up to the job is an open question. Of course that won’t stop the President from nominating him if he is intent on doing so; and, with a Democrat controlled Senate, there is little chance it won’t confirm Panetta, who is well liked in Washington, D.C.

Whether Mr. Obama and his next secretary of Defense get another four years will depend on many factors. How well the next secretary of defense performs is one of them.