Even though the number of active-duty personnel has remained flat or declined in recent years, the money spent on day-to-day operations will continue to grow, according to the bipartisan Congressional Budget Office (CBO). According to the agency’s Jan. 5 report on operations and maintenance:

Health care spending increased to $31 billion from $16 billion between 2000 and 2012.
Civilian compensation during the same period rose to $48 billion, up from $31 billion – not including health care.
Fuel costs rose during the period to $8 billion, up from $5 billion.