word | | Military service age and obligation |
| age | South Africa | 18 years of age for voluntary military service; women are eligible to serve in noncombat roles; 2-year service obligation (2007) |
| age | Spain | 20 years of age (2004) |
| age | Sri Lanka | 18 years of age for voluntary military service; 5-year service obligation (2007) |
| age | Sudan | 18-33 years of age for compulsory and voluntary military service; 12-24 month service obligation (2009) |
| age | Suriname | 18 years of age (est.); recruitment is voluntary, with personnel drawn almost exclusively from the Creole community (2007) |
| age | Swaziland | 18-30 years of age for male and female voluntary military service; no conscription (2008) |
| age | Sweden | 18-47 years of age for male compulsory or voluntary military service; conscript service obligation: 7.5 months (Army), 7-15 months (Navy), 8-12 months (Air Force); after completing initial service, soldiers have a reserve ... |
| 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 14 months (reducing to 1 year in 2009); women may enlist; women in Air Force service are restricted to noncombat roles ... |
| age | Tajikistan | 18 years of age for compulsory military service; 2-year conscript service obligation (2007) |
| 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 (2007) |