Department of Defense operations have changed rapidly in the last century, a speaker said Tuesday.

Jack Bell, deputy undersecretary of defense and principal adviser to the secretary of defense, said much of that change has come from recent interactions with enemies of the United States.

The Defense Department has had to modify its operations in Iraq and Afghanistan to reflect that changing situation, Bell said.

“This threat doesn’t come from a unified movement,” he said. “It comes from a highly fragmented, loosely organized group of people.”

He said there were certain characteristics of these groups that marked them as “terrorists.”

Most often, these groups will operate out of authoritarian states that politically support what they are doing or out of weak states like Afghanistan that cannot control what goes on inside of their borders, Bell said.

He said this change in the type of threat the Defense Department is facing, combined with flagging troop enlistment, has created a large amount of stress on military resources.

“U.S. military forces, in terms of manpower, in 1989 was at 2.1 million people – now it’s down to less than 1.4 million,” Bell said.

This has also introduced a new element to military operations, he said, that involves the use of outside contractors to heavily supplement the existing military forces in Iraq, Afghanistan and other parts of the world in which U.S. military operations are continuing.

“We have an increased reliance on contractors – not only here in our bases in the U.S., but to be deployed. Today, DoD has about the same number of DoD contractors in Iraq or Afghanistan as we have military forces,” Bell said.

He said another reason the military is relying more heavily on contractors is directly related to rebuilding efforts in countries the United States is occupying.

“There’s a term called the ‘golden hour,’ which begins during military intervention – really, when the first combat boots hit the ground – and extends for a period of only months,” Bell said. “It’s during this period when people decide which side they are going to support.”

He said one of the ways the United States can garner support for its cause is to begin rebuilding and repairing infrastructure immediately after it invades and topples a regime.

“This is a major change in the U.S. government’s traditional approach to combat operations. The traditional view was you go into the military operations and, when there are no longer security concerns, then you begin reconstruction. We really cannot afford that now,” Bell said.

However, one of the problems with this approach is that it requires a large amount of personnel that the military simply does not have at its disposal, he said.

One of the ideas used with outside contractors is that they are used not only for protecting the troops, but they also operate equipment, provide technical support to the troops and rebuild infrastructure in areas that have been invaded, he said.

Some of the problems this type of force has presented the Defense Department, Bell said, were the difficulties of managing both the troops and contractors and determining what legal responsibilities the contractors have.

“In 2006, Congress passed a law that applies the Uniform Code of Military Justice to our contractors,” Bell said.

He said the law meant that contractors, who were previously in a gray area of legal accountability, can now be tried for crimes they commit while out of the country.

Jared Graeve, senior in community and regional planning, asked Bell what percentage of the total cost of the Iraq war comprised hiring out contracts.

Bell answered the short-term economic costs were about the same as using only military personnel, but the long-term costs of contractors are actually lower because military personnel are actually more expensive to work with than contractors because of the benefits the military offers.