Indonesia's decision to name a new warship KRI Usman Harun, after Indonesian saboteurs executed in Singapore decades ago for the MacDonald House bombing in 1965, sets interesting posers for Indonesia-Singapore defence and foreign relations.

The 90m-long warship should not be welcome in Singapore territorial waters, as the so-named man-of-war would tear open old wounds sustained during a violent time in our bilateral relations.

While ties are presently warm and friendly, the passage of KRI Usman Harun in Singapore's waters will inevitably turn the spotlight on the campaign of urban terrorism Indonesia unleashed against our island-nation during an undeclared war which history records euphemistically as the Confrontation.

The choice of name would also ignite debate on what constitutes a "hero".

If the March 1965 attack on MacDonald House by the two Indonesian marines was staged in today's context, it would be clearly and unambiguously defined as urban terror, and elicit the same degree of condemnation, odium and disgust civilised people feel towards war waged against unarmed civilians by saboteurs who flee once their sinister deed has been triggered.

In essence, the bombing of MacDonald House by KRI Usman Harun's namesakes was carried out in that unseemly fashion. As soldiers, they obeyed their mission orders faithfully. This defence - that they were merely following orders - is the same smokescreen combatants brought to justice for crimes against humanity have hoisted to explain away or soothe over misdeeds like attacks on civilians.

As fate decreed, Singapore police caught the duo after an islandwide manhunt. The Indonesian saboteurs, Osman Mohamed Ali and Harun Said, were tried and convicted for murder and hanged in Changi prison in October 1968.

Executed as murderers in the Lion City, the dead marines were feted as heroes when their bodies were returned to Indonesia. News of their deaths angered Indonesian mobs, which sacked the Singapore Embassy in Jakarta.

Alas, if you thought Singapore has put this regrettable episode in our bilateral ties behind us and moved on, the past caught up with us this week.

So, while the vast majority of Singaporeans - youth and adults - would likely think of the fast-food chain upon hearing the word "MacDonald" in spoken form, we all received a refresher on our country's birth pangs when the Ministry of Foreign Affairs (MFA) shared its thoughts on the matter.

In response to media queries on Indonesian press reports on the naming of a warship as KRI Usman Harun, an MFA spokesman said: "The two Indonesian marines were found guilty of the bombing which killed three people and injured 33 others. Singapore had considered this difficult chapter in the bilateral relationship closed in May 1973 when then PM Lee Kuan Yew visited and scattered flowers on the graves of the two marines.

"Minister for Foreign Affairs K. Shanmugam spoke to Indonesian Minister for Foreign Affairs, Dr Marty Natalegawa, to register Singapore's concerns over the naming of the navy ship and the impact this would have on the feelings of Singaporeans, especially the families of the victims."

Three Singapore ministers have weighed in on this issue, underscoring the gravity of the matter. On Wednesday, Mr Shanmugam registered his concerns with his Indonesian counterpart. This was followed on Thursday with calls made by Deputy Prime Minister Teo Chee Hean and Minister for Defence Ng Eng Hen to their Indonesian counterparts to reinforce the point made by Mr Shanmugam.

We in Singapore should never forget the pain, the sorrow and the bloodletting, so senseless and indiscriminate, that the string of urban terror attacks inflicted upon countless Singaporean families during the Confrontation.

Attacks against civilians are a heinous act of war that no military should be proud of, a dishonourable blemish, a smear on the operational record of any self-respecting armed forces, a cowardly hit-and-run affair unworthy of hero worship.

That tainted record will be shouted out resoundingly at every foreign port of call, reminding foreigners both of the namesakes' dark deeds and Singapore's swift and decisive response to terrorism.

The KRI Usman Harun episode is a teachable moment for Singaporeans. It is another update to our National Education library from a country which coined the popular catchphrase "little red dot", a reminder of how the sensibilities and sensitivities of our small island-nation can be brushed aside by mindsets that see themselves as the strong armed cukong (power broker), the dominant entity in an imagined abang-adik (big brother-small brother) relationship rather than one where neighbouring states are viewed as equal, sovereign entities.

Singapore should tag KRI Usman Harun as a contact of interest as the warship is due to enter service later this year.

Republic of Singapore Navy (RSN) warships should politely decline any passage exercises with this vessel, as joint training with it would be a flirtation with a hull that fetes saboteurs who drew civilian blood on our soil.

Singapore's warships should never come alongside that ship, be it for a heaving line transfer or courtesy call on its deck. Imagine the odd and unfortunate picture of RSN officers dining in the wardroom of that ship with portraits of its dead namesakes staring down on the assembled ranks.

The RSN should further make it clear that that name plate will not be welcome within its naval bases, whether as part of the Exercise Eagle war games or naval shows like Imdex.

It is well within the sovereign rights of nations to call their warships anything they want.

It is also well within Singapore's sovereign right to decline the passage of men-of-war whose presence would reopen old wounds, whose show of flag would inflame and provoke anger and stoke memories of a deadly act of terrorism for which the authors paid with their lives.

stopinion@sph.com.sg

A former Straits Times defence correspondent, David Boey blogs on defence issues at kementah.blogspot.sg and is a member of the Advisory Council on Community Relations in Defence