In a clear signal that the courts will not tolerate national security being undermined by those who ignore the call to serve national service (NS), the High Court ruled that the "worst" category of NS defaulters - those who do not serve their obligations at all - will face close to the maximum of three years' jail.
This came as a three-judge panel allowed the prosecution's appeals for heavier sentences for three men, two of whom are brothers, who had dodged NS for varying durations.
Singaporean men have to register for national service when they reach the age of 16½ years and are obliged to serve up to the age of 40.
Ang Lee Thye, 43, who evaded NS for 23½ years - the longest possible under the Enlistment Act - was jailed for two years and nine months. He is serving his original two-year jail term and will now have to serve a longer one. He was 41 when he returned to Singapore from the US and was therefore no longer subjected to the Enlistment Act.
Sakthikanesh Chidambaram, 26, who evaded NS for five years, six months and 17 days, was jailed for 10 weeks, up from three weeks.
The NS defaulters
ANG LEE THYE, 43
He left Singapore with his family for the United States at the age of 14 in 1987. He did not respond when told to register for national service.
In 2009, he told the Central Manpower Base (CMPB) he would return only if he received "reasonable fines". In 2013, a month before his 40th birthday, he said he wished to return. He reported to the CMPB in January 2015 at the age of 41.
Default period: 23½ years
Initial sentence: Two years' jail
Current sentence: Two years and nine months' jail
SAKTHIKANESH CHIDAMBARAM, 26, AND VANDANA KUMAR CHIDAMBARAM, 23
Their Singaporean mother, who settled down in India, came back to Singapore to give birth to them in 1991 and 1993 respectively.
She took them back to India when they were still infants. They visited Singapore occasionally.
In 2008, Sakthikanesh was told to register for national service, but he left for university education in India. He returned to Singapore in April 2014 after completing his studies, and enlisted for NS in September that year. He has since completed his NS.
Default period: Five years, six months and 17 days
Initial sentence: Three weeks' jail
Current sentence: 10 weeks' jail
In May 2010, Vandana was told to register for NS. However, he returned to Singapore only in June 2014. He enlisted for NS in August that year. He has since completed his NS.
Default period: Three years, four months and two days
Initial sentence: $6,000 fine
Current sentence: Seven weeks' jail
Vandana Kumar Chidambaram, 23, who evaded NS for three years, four months and two days, was jailed for seven weeks. His initial sentence was a $6,000 fine.
Both brothers completed serving full-time NS last year.
In response to queries on the cases, the Ministry of Defence (Mindef) said on Wednesday that it takes a firm stand on those who commit offences under the Enlistment Act, adding that each case comes with its own circumstances which the Court will consider in deciding on the sentence.
"It is important that NS has the support and commitment of all Singaporeans. To achieve this, we have to adhere to the fundamental principles of universality and equity in NS," said a Mindef spokesman.
"If we allow Singapore citizens who are overseas to avoid NS or to choose when they want to serve NS, we are not being fair to the vast majority of our national servicemen who serve their country dutifully, and the institution of NS will be undermined."
The spokesman also touched briefly on the three cases.
For Ang, Mindef said that despite being advised to return to resolve his offences, the defaulter "chose to return to Singapore at an age when he could no longer be called up for NS at all, evading his NS obligations completely".
For the brother, Mindef said Sakthikanesh said he was aware of his NS obligations but chose to complete his university studies in India before returning to serve NS while Vandana was similarly aware of his NS obligations, as his father was in contact with the Ministry of Defence.
"Despite being aware of their NS obligations, they chose to evade NS to pursue their studies first," said the spokesman.
In considering the appeals, Chief Justice Sundaresh Menon said a key sentencing focus is deterrence to ensure those required to serve NS "do not evade their obligations or opt to postpone them to a time or on terms of their own choosing or convenience".
"Were it otherwise, over time, the attitude that national service can be done on one's own terms will weaken our national security and this is simply intolerable," he said.
The court said it will adopt, in a modified form, the sentencing approach suggested by the prosecution. Details of the framework will be elaborated on in due course.
The prosecution, represented by Solicitor-General Kwek Mean Luck, argued: "Lenient treatment of NS defaulters can invoke strong feelings of unfairness on the part of those who serve when called upon, and undermine public commitment to the institution of NS." He called for a signal to be sent to those who "game the system" that NS evasion will be met with stiff penalties.
He suggested a sentencing framework based on three categories. In cases where the default period exceeds two years but the defaulter is able to serve full-time NS in a combat role and reservist in full, he suggested a starting point of two to three months' jail.
At the other end, for those who evade NS for more than 20 years and are unable to serve full- time NS and reservist, he suggested a starting point of three years. For a default period of about 10 years or if the defaulter is unable to serve full-time NS in a combat role and reservist in full, he suggested two years' jail.
The court said that even if a defaulter performs well when he eventually serves NS, it is not a strong factor to get a shorter sentence.
Note: This story has been updated with Mindef's statement.