United States of America
conscription not enforced
The United States Constitution does not address military conscription. 
Compulsory military service is addressed in the Military Selective Service Act, which requires all males between the ages of 18 and 26 to register for compulsory military service (50 App. U.S.C., par. 453). The US Congress has the right to introduce compulsory military service for those registered if they think the national security necessitates forces greater than the regular armed forces (par. 451(d)). 
The right of the government to raise and maintain an army, including the right to conscript, has been recognized and upheld by the courts. While military service presently is voluntary, all 18-year-old youth are required to register with the Selective Service System, the civilian agency charged with conducting a military draft when required by law. The Military Selective Service Act provides for military conscription.
Enlistment in the armed forces is allowed from the age of 17.
Although enlistment in the armed forces is voluntary, the number of people from the lower social-economic classes in the armed forces is disproportionally high. In the US peace movement this is referred to as 'the poverty draft'. Likewise, the number of coloured people in the armed forces is also disproportionally high. Recent reports indicate that this trend is changing. The number of young black men who consider a full-time career in the armed forces has declined with 59 percent since 1989. The number of young white men considering such a career has also dropped, but only by 19 percent. 
2 Conscientious objection
There is no provision for conscientious objection to the compulsory military registration, but should Congress decide to call up conscripts for compulsory military service, they have the right conscientious objection as prescribed by Section 6(j) of the Military Selective Service Act, which states: "nothing contained in this title shall be construed to require any person to be subject to combatant training and service in the Armed Forces of the United States who, by reason of religious training and belief, is conscientiously opposed to participation in war in any form."  
Military personnel who develop a conscientious objection to military service may apply for reassignment to non-combatant duties or discharge from the Armed Forces under Department of Defense Directive 1300.6.   
This Directive sets out the full procedure for achieving CO status. CO status is only granted to a CO "who is conscientiously opposed to participation in war in any form; whose opposition is found on religious training and belief; and whose position is sincere and deeply held."
The final decision on the application is taken by the headquarters of the military service concerned. 
Before the 1990 Gulf War started, some 2,000 military personnel were granted CO status.
During this war the right to conscientious objection was suppressed. Of those who refused to serve and announced they were COs, 42 were imprisoned at Camp Lejeune, some of them charged with 'desertion in wartime'. They were released at the end of 1992.  
3 Draft evasion and desertion
Refusing to register for compulsory military service is punishable by up to 5 years' imprisonment and a USD 250,000 fine. Moreover, those who fail to register are denied federal financial aid for education and for job training.  
Desertion is punishable under art. 85 of the Uniform Code of Military Justice (10 U.S.C. para. 885). In peacetime desertion may be punished by up to five years' imprisonment, if the desertion was intended to avoid hazardous or important duties. Otherwise, the maximum penalty is three years' imprisonment or two years' if the deserter voluntarily returns to the military. The penalty for desertion may also include dishonourable discharge from the armed forces and forfeiture of all pay and allowances. 
In the early 1980s more than a million resisted the military registration, but only some 20 were prosecuted. Their sentences ranged from a year's community service to three years' imprisonment, no-one actually serving more than 5 months in prison. Nowadays non-registrants are denied federal financial aid for education and for job training, and are barred from federal government employment.  
Conscription ended on 1 July 1973 following the end of the Vietnam war and the withdrawal of US troops from Vietnam. The registration for the draft ended in 1975. The draft registration system was set up again in 1980 under the President Carter administration.   
6 Annual statistics
In 1997 the armed forces were 1,447,600 strong - about 0.54 percent of the population. 
Between 1983 and 1988 on average 175 CO applications were approved annually. 
 UN Commission on Human Rights 1980. Report by the Secretary-General. United Nations, Geneva.  Mager, Andy 1988. United States Report to International Conscientious Objectors' Meeting (ICOM). War Resisters' League, New York.  NISBCO 1990. Who is a Conscientious Objector? leaflet, November 1990. NISBCO, Washington DC.  War Resisters League 1991. Letter to WRL members, June 1991. WRL, New York.  Moskos, C.C., J.W. Chambers II 1993. The New Conscientious Objection, from sacred to secular resistance. Oxford University Press, New York/Oxford.  Abecassis, L., P. Duong, S. Perrier, N. Watt, 1994. Conscription Militaire ou Service National a Option Civique, rapport de l'enquête préliminaire effectuée auprès d'une vingtaine d'Etats membres de l'UNESCO. CCIVS - UNESCO, Paris.  UN Commission on Human Rights 1994. Report of the Secretary-General prepared pursuant to Commission resolution 1993/84 (and Addendum). United Nations, Geneva.  Toney, R.J. 1996. Military Service, Alternative Social Service, and Conscientious Objection in the Americas: A Brief Survey of Selected Countries. NISBCO, Washington DC, USA.  US Department of Defense, Office of General Counsel 1996. Response to CONCODOC questionnaire, 3 September 1996.  Institute for Strategic Studies 1997. Military Balance 1997/98. ISS, London, UK.  McHugh, Jane 1996. 'Young, gifted, black - but not in the army', in: Army Times, 20 May 1996.