"Men who have attained the age of eighteen may be required to serve in the Armed Forces, in the Federal Border Police, or in a civil defense organization."
There is an extension to Article 12: Article 12a says that the state can force men to join the Bundeswehr - the German army. Up until 2011, all fit men aged 18 and over had to service the German military for nine months during which they learned how to use weapons and get familiarised with inner workings of the German army. Those who object the idea can choose to take another form of service for 12 months- they can, for instance, work in a hospital. Since 2011, the obligation for young men to join the "Bundeswehr" has been lifted. Today men and women can join the German military voluntarily.