Anything else is totalitarian socialist drivel.
From the United States Code
CITE 10USC Sec 311
EXPCITE TITLE 10 - ARMED FORCES
Subtitle A - General Military Law
PART I - ORGANIZATION AND GENERAL MILITARY POWERS
CHAPTER 13 - THE MILITIA
HEAD Sec. 311. Militia: composition and class>/i>
STATUTE (a) The militia of the United States consists of all able-bodied males at least 17 years of age and, except as provided in section 313 of title 32, under 45 years of age who are, or who have made a declaration of intention to become, citizens of the United States and of female citizens of the United States who are members of the National Guard.
(b) The classes of the militia are -
(1) the organized militia, which consists of the National Guard and the Naval Militia; and
(2) the unorganized militia, which consists of the members of the militia who are not members of National Guard or the Naval Militia.
Since all males between the ages of 17 and 45 are already members of the Unorganized Militia, the draft serves merely to call a needed number of them to active duty, hence the designation Selective Service. Remember this law has been part of the Federal Code since the 1790s and has nothing to do with socialism, but concerns the duties of citizens in a free Republic.