THE INDONESIAN CONFRONTATION
Indonesia's foreign minister, Dr Subandrio, on behalf of President Sukarno, declared Konfrontasi or Confrontation on Jan 20, 1963.
President Sukarno, who had opposed the formation of Malaysia, which included Singapore, hoped to demoralise its people into accepting "accommodation" with Indonesia as the only way to have peace.
Indonesians were instructed to sabotage important installations and public utilities such as the Pasir Panjang Power Station, petroleum refineries in Singapore, the main water pipeline from Johor to Singapore, bridges and military installations.
When the Federation of Malaysia became official in September 1963, Indonesia broke off diplomatic relations with Malaysia.
After that, Indonesian saboteurs caused at least 42 explosions in Singapore, including at the water pipeline, Istana, Raffles Hotel, the Royal Air Force's Changi base, schools and houses.
Seven people were killed and more than 50 were injured in the blasts.
On Aug 11, 1966, Confrontation formally ended with the signing of a peace agreement between Malaysia and Indonesia.
It had receded into the background of Indonesian politics about a year earlier after an attempted coup led to the removal of President Sukarno and the purge of the Communist Party of Indonesia, the major proponents of the Confrontation policy.
When the MacDonald House bombers were hanged on Oct 17, 1968, the Singapore Embassy in Jakarta was stormed, with furniture smashed and the Singapore flag torn.