(1989), the plaintiff argued that the 1989 amendments to the Constitution had violated the basic features of the Constitution by breaching the principle of separation of powers by usurping judicial power, and contravening the rule of law. The Court rejected the application of the basic features doctrine owing to the differences in the making of the Singapore Constitution and the Indian Constitution, and the fact that the framers of the Singapore Constitution had not expressly provided for limitations to be placed on Parliament's power of amendment. The Court also held that, in any case, there had been no violation of the Constitution's basic features on the facts of the case. On appeal, the Court of Appeal determined the case on other grounds, and thus found it unnecessary to decide conclusively if the basic features doctrine applies in Singapore. Role of the judiciary in national security matters There are competing views over the appropriate role of the judiciary in matters concerning preventive detention under the ISA. A related concern is whether the judicial process is suitable for such matters. The legislative and constitutional amendments relating to judicial review under the ISA were intended to limit the role of the courts in national security matters. In 1989, Law Minister S. Jayakumar argued in Parliament that the amendments were needed because the courts would effectively be responsible for national security matters if judicial review was permitted. The subjective test was deemed necessary to reserve to the executive the responsibility for national security matters, and to enable the Government to deal effectively with security threats. Tham Chee Ho contends that, based on the objective test set out in Chng Suan Tze, the fear that the courts will take over responsibility for national security matters is misplaced. This is because the courts do not review the actions taken by the executive for national security purposes, but merely determine whether the situation in fact involves national security issues. The Court of Appeal in Chng Suan Tze reflected this by holding that what was required to preserve national security was a matter solely for executive judgment. Another reason that was put forward by Jayakumar to justify a limited role by the judiciary was that the judicial process is unsuitable for deciding preventive detention issues. Persons who are potential threats to national security may act covertly, hindering the collection of evidence to secure a conviction in a court