word | | Military service age and obligation |
| age | Swaziland | 18-30 years of age for male and female voluntary military service; no conscription (2008) |
| age | Sweden | 19 years of age for compulsory military service; conscript service obligation: 7-15 months (Navy), 8-12 months (Air Force); after completing initial service, soldiers have a reserve commitment until age 47 (2006) |
| age | Switzerland | 19 years of age for male compulsory military service; 18 years of age for voluntary male and female military service; the Swiss Constitution states that "every Swiss male is obliged to do ... |
| age | Syria | 18 years of age for compulsory military service; conscript service obligation - 30 months (18 months in the Syrian Arab Navy); women are not conscripted but may volunteer to serve (2004) |
| age | Taiwan | 19-35 years of age for male compulsory military service; service obligation 16 months (to be shortened to 14 months as of July 2007 and to 12 months in 2008); women may enlist ... |
| age | Tajikistan | 18 years of age for compulsory military service; 2-year conscript service obligation (2006) |
| age | Tanzania | 18 years of age for voluntary military service (2007) |
| age | Thailand | 21 years of age for compulsory military service; 18 years of age for voluntary military service; males are registered at 18 years of age; 2-year conscript service obligation (2006) |
| age | Timor-Leste | 18 years of age for voluntary military service; no conscription (2008) |
| age | Togo | 18 years of age for selective compulsory and voluntary military service; 2-year service obligation (2006) |
| age | Tonga | 18 years of age (est.); no conscription (2008) |
| age | Trinidad and Tobago | 18 years of age for voluntary military service (16 years of age with parental consent); no conscription (2008) |
| age | Tunisia | 20 years of age for compulsory military service; conscript service obligation - 12 months; 18 years of age for voluntary military service (2007) |
| age | Turkey | 20 years of age (2004) |
| age | Turkmenistan | 18-30 years of age for compulsory military service; 2-year conscript service obligation (2006) |
| age | Uganda | 18-26 years of age for compulsory and voluntary military duty; 18-30 years of age for professionals; 9-year service obligation; the government has stated that recruitment below 18 years of age could ... |
| age | Ukraine | 18-25 years of age for compulsory and voluntary military service; conscript service obligation - 18 months for Army and Air Force, 24 months for Navy (2004) |
| age | United Arab Emirates | 18 years of age (est.) for voluntary military service; 18 years of age for officers and women; no conscription (2008) |
| age | United Kingdom | 16-33 years of age (officers 17-28) for voluntary military service (with parental consent under 18); women serve in military services, but are excluded from ground combat positions and some naval postings; must ... |
| age | United States | 18 years of age; 17 years of age with written parental consent (2006) |
| age | Uruguay | 18 years of age for voluntary and compulsory military service; enlistment is voluntary in peacetime, but the government has the authority to conscript in emergencies (2007) |
| age | Uzbekistan | 18 years of age for compulsory military service; conscript service obligation - 12 months (2004) |
| age | Venezuela | 18 years of age for compulsory and voluntary military service; conscript service obligation - 30 months; all citizens of military service age (between 18 and 50 years old) are obligated to register for ... |
| age | Vietnam | 18 years of age (male) for compulsory military service; females may volunteer for active duty military service; conscript service obligation - 2 years (3 to 4 years in the navy); 18-45 years of ... |
| age | Zambia | 18 years of age for voluntary military service (16 years of age with parental consent); no conscription (2008) |