Singapore is at a crossroads.
Community cases here are now extremely low, with just six in the past fortnight.
This means measures to contain the virus here are working and Singapore should be able to significantly ease them with little risk, experts have pointed out to The Straits Times.
Singapore can also open up its borders to visitors from countries with equally low spread of the virus.
But it should not do both, the experts cautioned.
Every easing of measures, whether internally or in terms of border control, increases risks. Doing too much too soon could result in a major second-wave outbreak, they explained.
Singapore has decided on opening its borders, with the promise of a slight easing of domestic measures, provided the infection numbers stay low.
People in general have welcomed the move that allows for easier travel without the need for a 14-day quarantine.
But allowing travel to resume, even in a controlled manner, exposes the country to the risk of imported infections that could spread to the community, the experts said.
Globally, there are more than 400,000 new Covid-19 infections and about 5,000 deaths a day.
With winter approaching in the Northern Hemisphere, there are fears the numbers may surge.
While this is not the best time to allow freer travel with countries there, holding off would mean a delay of several months.
Professor Teo Yik Ying, dean of the National University of Singapore's Saw Swee Hock School of Public Health, said Singapore must be careful about which countries it opens its borders to.
"There are certainly low-risk countries and territories, including New Zealand, Hong Kong, Taiwan, Thailand, Vietnam, Australia and China, where public health and border control measures are sensible, effective, and implemented and enforced well," he said.
"At the other end of the spectrum, there are high-risk countries where there are rampant transmissions in the community, in part because of inadequate or poorly enforced measures."
Associate Professor Alex Cook, vice-dean of research at the school, noted that if the prevalence of Covid-19 in the other country is the same as in Singapore, "there's no extra risk from having people travel from one to the other, and even less risk if there's pre-departure and on-arrival testing".
Dr Asok Kurup, who chairs the Academy of Medicine's Chapter of Infectious Disease Physicians, questioned why Singapore is opening its doors to Indonesia, which is facing thousands of new infections daily.
Singapore has also announced green lane travel with Germany, which is seeing thousands of new Covid-19 infections daily and has gone into lockdown.
"Countries which have not had a sustainable mitigation of cases should not be considered for reciprocal green lane travel," Dr Kurup said.
The travel arrangements vary with each country. Some involve the need to adhere to strict itineraries, while for others, visitors are free to roam at will.
Though travellers need to be tested before their journey and/or on arrival, the risk in allowing travel to resume lies in foreigners bringing the virus here, as well as Singaporeans getting infected overseas and returning undetected.
Testing picks up only people who are infected, and not those who have the virus in them during the incubation period.
Prof Cook said: "Replacing quarantine with pre-and post-departure testing might filter out 80 per cent to 90 per cent of the cases, depending on what tests you're doing."
While opening borders will raise the risk of bringing in the virus and reintroducing Covid-19 to the community, not opening the borders will have a major negative impact on the economy and jobs.
Singapore has always looked to the world as its hinterland. Business travel and tourism are a major contributor to the economy, not just bringing in money, but also providing tens of thousands of jobs in related sectors.
Tourism accounted for 4 per cent of gross domestic product last year, or close to $20 billion in direct contribution.
Aside from that, ease of travel is one of Singapore's selling points in attracting investments.
As Transport Minister Ong Ye Kung told Parliament earlier this month: "When a company puts a significant investment in Singapore, one key reason for them to do that is our superior air connectivity because that means their customers, suppliers, partners and key executives can travel in and out of Singapore easily."
He added: "The longer our borders remain closed, the greater the risk of losing our air hub status and our attractiveness as a place to invest, and to create jobs because of those investments."
Experts interviewed are confident that Singapore will be able to handle any import of the virus, with cooperation from the public.
People here must continue to disinfect their hands, wear masks and ensure they stand a metre away from the next person. The curbs on large gatherings should stay. This will limit the spread of the virus should travellers bring it in.
Prof Cook said: "I'm sure that we will see clusters caused by importation, but it's worth highlighting that the measures we have in place have been able to contain community transmission since June."
Dr Kurup added: "I don't think we will fall back to the grim earlier days, provided we maintain current public health measures which need to be sustained."
Prof Teo said that if measures here are eased significantly and large gatherings are permitted, then any community spread could happen "at an accelerated pace".
But if the measures are properly adhered to, and gatherings are capped and controlled, the spread can be contained at manageable levels, even if there are leakages from travellers, he said.
Also, Singapore is far more prepared today than it was at the start of the year, when infected visitors brought the outbreak here. Close to 58,000 people have been infected and 28 people have died.
Said Prof Cook: "Back then, we did not have the testing capacity we have now, we didn't have all the adjuncts to our contact tracing (TraceTogether and SafeEntry) we have now, and mask wearing was not mandated."
Professor Dale Fisher, a senior infectious diseases expert at the National University Hospital, agreed. "Measures such as masking, safe distancing and limiting the size of gatherings are key to opening our borders."
He said that while opening up to visitors is not without risks, "it is not a risk without benefit". "In fact, it's a small risk with huge benefit. I am confident Singapore can manage extra cases if they occur."
Professor Leo Yee Sin, executive director of the National Centre for Infectious Diseases, said Singapore has been able to keep community cases low on account of "the effort and cooperation of everyone in the community".
Countries with less strict measures and are open to travel continue to see a large number of daily infections and deaths.
Prof Leo said relaxing border controls and other measures "must be calibrated with the ability to cushion the downside".
Countermeasures must also be in place and rolled out quickly if required. These include tweaking border controls should numbers surge.
Prof Cook said the impact of allowing freer travel with partner countries depends on three factors: how many people arrive in a day, what is the incidence in the source country, and what fraction of infected travellers is filtered out through border measures.
"If we're only admitting a handful of businessmen or women, or visiting dignitaries, then we can accept a more porous net. If we're hoping for mass tourism with tens or hundreds of thousands of travellers a day, then we need a net that will catch cases more thoroughly," he said.
However, even with no quarantine required, Singapore is unlikely to see a flood of tourists, given the cost of the test, which is about $200 here.
Since Sept 1, visitors from Brunei and New Zealand have been allowed in without quarantine requirements, but there has been no large influx so far. They have not reciprocated the arrangement for Singaporeans wanting to go there.
Singapore is also setting up a travel bubble with Hong Kong. This is a two-way agreement, and unlike green lane arrangements with some countries, allows for unstructured leisure travel.
The Government is also indirectly encouraging people here to travel by providing free Covid-19 tests on their return and subsidised treatment, as well as insurance coverage should they be infected.
Previously, when travel was discouraged, those who left Singapore after March 26 had to pay the full cost of any Covid-19 infection diagnosed within 14 days of their return. Their treatment was also not covered by their health insurance.
As some of the experts noted, how successful the relaxation of travel curbs proves to be in safely boosting the economy will depend on people's willingness to travel while the pandemic is raging, and on people here strictly adhering to protective measures to prevent a massive outbreak.
But one thing is clear: It will not be exactly like old times.
As Prof Leo said: "It is important to mentally prepare that life will not be the same as before Covid-19."