The acrimony that once characterized Singapore's relationship with Malaysia began to change in the 1980s when the two countries adopted a course of reconciliation. The improvement in relations began when Mahathir Mohamad became prime minister of Malaysia. Lee Kuan Yew and Mahathir achieved a personal rapport that established the tone for a rapprochement, but Singapore's expulsion from Malaysia in August 1965 continued to color the relationship. Singapore's primary concern was that Malaysia maintain a political system that tolerated multiracialism. In Singapore's view, the undermining of this political principle in Malaysia would have regional ramifications. Regional tolerance of multiracialism, for example, might be reduced if an Islamic revival in Malaysia led to the establishment of an Islamic state and the status of Malaysia's Chinese population were subsequently endangered.

Singapore was linked with Malaysia militarily through the 1971 Five-Powers Defence Arrangement (see Glossary), an arrangement under which the security of Singapore and Malaysia was guaranteed by Britain, Australia, and New Zealand. Singapore cooperated with both Malaysia and Indonesia in maintaining the security of the Malacca and Singapore straits. Another link with Malaysia was the Inter-Governmental Committee (IGC), a forum established in 1980 for the informal discussion of bilateral issues by delegations headed by each country's minister for foreign affairs.

Data as of December 1989