Definitions of militia on the Web:
* civilians trained as soldiers but not part of the regular army
* the entire body of physically fit civilians eligible by law for military service; "their troops were untrained militia"; "Congress shall have power to provide for calling forth the militia"--United States Constitution
Needed? The militia is embedded in the Constitution:
The Congress shall have power
To provide for calling forth the militia to execute the laws of the union, suppress insurrections and repel invasions
and in the Bill of Rights:
A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.
It's not just needed, it's part of the foundation of our country.