Singapore and Indonesia have, despite periodic tensions, managed to maintain warm and friendly bilateral ties for half a century.

That is no mean feat in a world where international harmony is regularly threatened by political turmoil, regional conflicts, global financial crises as well as Islamic extremism.

Relations between the two founding members of Asean have largely been underpinned by strong economic and defence cooperation. This largely began under Singapore's founding prime minister Lee Kuan Yew and former Indonesian president Suharto - two leaders whose friendship had ensured stability and mutual prosperity.

The second Singapore-Indonesia Leaders' Retreat between Prime Minister Lee Hsien Loong and President Joko Widodo, to be held in the city-state tomorrow, will undoubtedly build on that shared legacy.

With growth a key focus for Mr Joko since he was elected in 2014, more economic collaborations and business tie-ups between the two countries are naturally expected.

But questions have been raised over how the bilateral relationship will evolve, as both countries enter new phases of development, and possible paradigm shifts in political leadership.

The latter has already occurred in Indonesia where, in President Joko, the country has its first elected leader without any links to the old political elite.

His style of governing, said to centre on the Javanese philosophy of sugih tanpa bandha, or being a humble servant-leader, is admired by his people but also often seen as unpredictable by political operatives.

Foreign policy hacks, more used to the established patterns of past Indonesian politicians, are also regularly unnerved because they have been unable to decipher Mr Joko's unconventional approach as head of state.

This trend will continue amid the Indonesian people's hunger for change, which has led to the rise of a new generation of leaders like Mr Joko, as well as others who have been breaking through the ranks of the old establishments, often from cities and regions outside Jakarta.

The prevailing view is that many Singaporeans today, including some members of the Civil Service, do not have sufficient understanding or knowledge of Indonesia, particularly on the political networks beyond the country's capital.

That is why Dr Leonard Sebastian, an associate professor from the S. Rajaratnam School of International Studies, has been advocating the need for more people-to-people engagements, including exchanges between young Singaporeans and Indonesians.

"We cannot depend on the type of rapport between Mr Lee Kuan Yew and Mr Suharto," said the veteran academic in South-east Asian affairs.

"We need to build new relations and partnerships because within the next five to 10 years, we will have to deal with a new group of people we have no feel for."

Mr David Boey, a long-time observer of the Indonesian military, and former defence correspondent for The Straits Times, who has covered the country extensively, agrees with Dr Sebastian.

"One should not discount the value of personal relationships where phone calls between leaders can pave the way for a mutually beneficial outcome," said Mr Boey.

The member of Singapore's Advisory Council on Community Relations in Defence said that although it is natural to ask how ties can keep rising to the "proverbial next level", it is the next generation that matters more.

PM Lee and Mr Joko's continuation of the pertemuan empat mata, or four-eye meetings, which helped stabilise ties during the Lee Kuan Yew-Suharto era, is a sign of improving bilateral relations in a new age.

But the jubilee celebrations tomorrow are also an opportunity for the current leaders to set the tone for future engagements, possibly beyond government or economic collaborations, and shift towards more exchanges between their people.

Stronger people-to-people ties will not only ensure that the two neighbours remain close and have a robust bilateral relationship, but also help maintain stability in the region amid episodic tensions.

The question is: Will everyday Singaporeans or Indonesians recognise the true value of this friendship to put more effort towards learning about each other?