"Article I, Section 8, of the U.S. Constitution vests Congress with broad powers over the armed forces, including the power "To raise and support Armies" and “To provide and maintain a Navy.” As such, the size of the armed forces is a topic of perennial congressional interest and debate. Congress annually sets minimum and maximum strength levels for the active components and maximum strength levels for the reserve components.
The House and Senate versions of the National Defense Authorization Act (NDAA) for FY2017
authorized differing levels for active duty personnel in each of the services, but these
authorizations diverge most significantly with respect to the Army. The Senate version of the
FY2017 National Defense Authorization Act approved Army end strength of 460,000 soldiers,
while the House version approved an Army end strength of 480,000. The Senate figure represents
a decrease of 15,000 soldiers in comparison to the Army’s FY2016 end strength of 475,000, while
the House figure represents an increase of 5,000..."