If you've engaged in overseas armed conflict — or even if you haven't acted upon your intention to do so — prepared to be dealt with by the Internal Security Act. According to the Ministry of Home Affairs, that's what happened to four radicalised Singaporeans in separate cases.
For Mohammad Razif Yahya, 27, and Amiruddin Sawir, 53, they were detained in August 2015 for voluntarily taking up arms and being a part of the sectarian conflict in Yemen.