Defense Secretary Donald Rumsfeld has begun defending the Pentagon's sweeping base closure plan.
He told the panel that will review the proposal the changes are essential in a time of war.
The proposal involves closing or consolidating 62 major bases, and changes to dozens of others.
Rumsfeld says the changes are needed to deal with the "new demands of the war against extremism and other evolving challenges in the world."
The head of the Base Realignment and Closure Commission told Rumsfeld the proposals, if accepted, will have "profound effects" on the communities and the people who work at them.
Rumsfeld promises the government would provide a variety of help to communities and people whose bases end up being closed.