Prompted last month by Defense Secretary Donald Rumsfeld to consider ways to make more personnel available for duty in Iraq, the Marine Corps is advancing a proposal to increase its overall size by 3,000 to 5,000 Marines -- a boost service officials say could allow for the reconstitution of key units abolished during the post-Cold War drawdown. Pentagon officials familiar with the Marine Corps move to create a new regimental combat team say it would require increasing the service's budget,...