It's a diplomatic row that stretches back half a century, tainting Singapore-Indonesia relations with memories of a bomb, bloodshed and executions.
Now the notorious Orchard Road blast of 1965 is back in the spotlight, thanks to Jakarta's decision this month to name a warship after the bombers, who were a pair of undercover Indonesian marines.
Political experts believe the recently reopened wounds are unlikely to spur physical confrontation or economic fallout - but caution that they may continue to fester, especially since neither side feels it can afford to appear weak in a region with a history of strife.
Indonesia is already preoccupied with an upcoming election, and has major differences with Australia over asylum seekers and allegations of spying. Jakarta might have to engage in some delicate diplomacy with Singapore, especially since it is the wealthy city state's third largest trade partner.
The problems began after Jakarta officials confirmed they will name a navy vessel "KRI Usman- Harun" after Usman Haji Mohamed Ali and Harun Said - the two marines who bombed an office building in Singapore's main shopping district on March 10, 1965.
The explosion left three dead and 33 injured. The two marines, who were acting under orders, were convicted and hanged three years later by Singapore authorities. But they were hailed as heroes back home in Indonesia, where there were protests over their executions.
Personal calls from Singapore ministers to their Indonesian counterparts to reconsider the naming - and spare a thought for the families of the victims of the bombing - failed to break the diplomatic impasse.
Political analysts say Singapore, which will be celebrating its 50th anniversary of independence next year, will not let the matter rest.
"The political terrain in Singapore has changed and Singapore leaders cannot be seen to be lax in handling an issue that touches a raw nerve for many Singaporeans," said Dr Mohamed Nawab, an expert in Indonesian and Malaysian politics and foreign policy at the S. Rajaratnam School of International Studies in Singapore. "I think relations in the long term are likely to be affected unless the Indonesian government apologises for its current actions."
The bomb blast was part of the then Indonesian president Sukarno's policy of konfrontasi (confrontation) against the Federation of Malaysia which formed in September 1963.
Sukarno was against the idea of Malaya, Singapore, Sarawak and Sabah joining to form the federation, which he felt would only serve British interests as a puppet state.
Sukarno's regime sent groups of saboteurs to the federation to create trouble. Numerous bombs that were set off in Singapore, but most were minor compared to the Orchard Road attack.
Relations between the two nations improved only after Singapore's first prime minister, Lee Kuan Yew, visited Jakarta and scattered flowers at the graves of the two marines in 1973 following much careful consideration by Singapore.
Amid the current spat, Singapore cancelled invitations to the Indonesian Navy chief and some 100 Indonesian delegates to attend the Singapore Airshow. Other Indonesian military leaders then pulled out.
Speculation is rife about why Indonesia would want to revisit old wounds.
Mohamed Nawab said: "Politicians in Indonesia have often used Singapore and Malaysia as whipping boys to enhance their nationalist credentials.
"Given that the coming election is likely to be a tough one for the Partai Demokrat [The Democratic Party led by President Susilo Bambang Yudhoyono], they are using this issue for their political purposes. It is likely to be driven by political expediency on the part of the current leadership that is fully cognizant of the Indonesian people's nationalist fervour," he said.
Observers say both sides will eventually move on.
"In fact, the nature of the spat is far less serious than allegations from last year that Singapore helped the United States and Australia tap telephone conversations by senior Indonesian officials," said assistant professor Ja Ian Chong from the National University of Singapore. "If Singapore and Jakarta were able to overcome the flap from last year, I am confident that relations will be able to weather the current furore."
Documents leaked by American whistleblower Edward Snowden last year alleged that Singapore was involved in US-led spying operations of countries in the region including Indonesia and Malaysia.
Meanwhile, Singapore has raised concerns over possible haze covering the island next week due to forest fires in Indonesia.
The fires and the smog have been an annual issue. Last year, the amount of pollution hit record levels with the city skyline barely visible for a few days.
In a Facebook post, Environment and Water Resources Minister Vivian Balakrishnan had said: "We will try to encourage them to take action - but we all know the welfare of close neighbours is not their priority."