By Frida Ghitis Courtesy  CNN

(CNN)The first time I traveled to Sri Lanka, in 2010, a ghastly civil war had just ended. Military officers still manned checkpoints along major roads.

Frida GhitisWhether we were passengers in a rickety tuk-tuk in Colombo, the bustling, leafy capital, or riding in an air-conditioned car across the countryside, armed men in olive-green uniforms would routinely order us to stop. They would check for explosives or for any sign that the violence that had plagued the country over nearly three decades might again threaten the peace won at such an appalling cost.Those scenes seemed relegated to the past — until this week when terrorists killed hundreds of people, attacking churches and major hotels on Easter Sunday. At last count, more than 320 people are confirmed dead and hundreds more injured.A decade ago, it made sense to me that travel brochures routinely referred to the country as a “teardrop shaped island.” Tears and Sri Lanka seemed to belong in the same sentence. I thought that had changed.Up to 100,000 people died in a horrific civil war that ended in 2009. All wars are awful, but there was something particularly macabre about Sri Lanka’s — with its wave of suicide bombings by the fanatical Tamil Tigers; with its gruesome final battle — a civilian massacre by the government; with the still-visible scars in Jaffna, the capital of the Northern Province, and the rest of the battered war zones, where the radical members of the Tamil minority launched their brutal bid for independence, drawing a crushing response from the state.

I lived through Sri Lankan terrorism. Here’s my adviceI returned over the years, witnessing a country emerge from tragedy. On my most recent trip, 16 months ago, I stayed at Colombo’s lively Cinnamon Grand Hotel, one of the targets of the Easter Sunday attacks. I had breakfast every day — fish curry and chilled coconut juice — in the same restaurant where a suicide bomber detonated his explosives. I watched the lavish weddings in the cavernous rear lobby, soaking up performances from traditional Sinhalese musicians and trying to understand the symbolism of the rituals.I rejoiced as a witness to Sri Lankans enjoying the fruits of peace: a normal life.For the rest of the world, peace meant that the wonders of the small island in the crosscurrents of history were open and inviting. Tourists started arriving by the millions. But all was not well on the island known before independence as Ceylon, and before that as Serendib, the inspiration for the word “serendipity.”After the war, Sri Lanka moved haltingly along the path of transitional justice, drawing international support but also criticism. Separately, domestic political battles reached dangerous levels. Last year, a constitutional clash between rival politicians left the country with competing prime ministers amid warnings that the country risked plunging back into a bloodbath. The police canceled vacations just in case.The country’s giant neighbors, China and India, have vied for influence. Former President Mahinda Rajapaksa, close to China and accused of massive corruption, signed a gargantuan deal with Beijing for construction of a new port. Rajapaksa has denied the accusations. The cost was so high that Beijing ended up taking possession of the strategic facility, infuriating Sri Lankans.

Mystery surrounds the source of the Sri Lanka attacksChina’s presence is inescapable. I once visited what would become another target of Sunday’s terrorists, the Shangri-La Hotel, a massive, luxurious structure facing the seashore, where Chinese workers are building yet another mammoth controversial project, this one building up in the sea. (China generally sends its own laborers to work on its foreign infrastructure projects.)The economy has been performing well since peace returned. Gross domestic product, the poverty rate and life expectancy have all been moving in the right direction. And yet not long ago I noted that “the march toward a stable, peaceful and prosperous future is threatened” by the government’s hesitancy in dealing with the past and its reluctance to tackle emerging tensions.Those new tensions include friction between Buddhists and Muslims, which burst to the surfaceduring one of my visits.According to the 2012 census, some 75% of Sri Lankans are ethnic Sinhalese, most of them Buddhists. Ethnic Tamils, the largest minority, make up little more than 11%. Most of the them practice Hinduism. Muslims make up just under 10% of the population, and Christians, most of them Catholic, are 7.6 % of the population.Clearly, it’s a complicated country, shaped by the sweep of empires and merchants who brought their religions with them. For the most part, the different groups have and continue to live in peace, but the exceptions have proven catastrophic enough to warrant alarm.Authorities are blaming an Islamist group, National Tawheed Jamath, for the carnage, saying it probably had help from abroad. Multiple warnings of an impending attack suggest that line of thinking is reasonable, and now ISIS has claimed responsibility.

Concerns terror cell in Sri Lanka large and well-connected 05:11One of the greatest risks now is that in its fully justified effort to uproot the organization that carried out Sunday’s attacks, the authorities may further spread the seeds of extremism, giving terrorists precisely what they want. Fanatics intent on sparking unrest, on boosting recruitment and weakening the state like nothing more than to see the state make life worse for their potential supporters.Decisive action is required, but let’s hope cool thinking prevails. Sri Lanka’s peace is fragile.Authorities were wise to block much of social media after the attacks. Fueled by rumors in Facebook posts, mobs of nationalist Buddhist extremists (you read that correctly) have clashed against Muslim groups. The government, dominated by Sinhalese Buddhists, has been slow to act. After one such attack, in 2017, the Sri Lankan human rights lawyer Gehan Gunatilleke told me that the government’s inadequate response is “legitimizing ultra-conservative” Muslim groups, noting that some of the Muslim groups are trying to outdo each on their radicalism to please their Middle Eastern backers.Follow CNN Opinion

Join us on Twitter and FacebookIt’s the perfect brew for extremism to thrive.Over the years I’ve met heroic Sri Lankans who fought to bring peace to their country. I’ve met Sinhalese and Tamils working for reconciliation. And I’ve heard worried Sri Lankans concerned about politicians squandering the country’s future. The checkpoints have been lifted. Peace has made inroads, but the shadow of the long war has not completely faded. Sri Lankans, heartbroken after the bombings, understand better than anyone how much is at stake.This commentary has been updated from an earlier version to add that China often sends its own laborers to work on Chinese infrastructure projects in other countries.