Ten years after the Bali bombing, Indonesia's president said the "monstrous act of terror" failed in its aim of fracturing the nation.
Susilo Bambang Yudhoyono's comments came as 2,000 police and military personnel, including snipers, were deployed across the island, after "credible information" of a threat to today's commemorations.
Bali's deputy police chief I Ketut Untung Yoga Ana said authorities were "ready to tackle any kind of terror threat" during the event, attended by Australian Prime Minister Julia Gillard.
The bombings in the predominantly Muslim nation on October 12, 2002, by al-Qaeda-linked group Jemaah Islamiyah, opened an Asia front in the war on terrorism a year after the September 11, 2001, attacks on the US.
More than 200 people died in the blasts on Bali's party strip - mostly Western tourists, but also including 38 Indonesians.
Yudhoyono, who was security affairs minister at the time, said the atrocity had only brought the country closer together. "Whatever the motivation and calculation of the terrorists, the Bali bomb attack did not produce its desired effects," he wrote in The Sydney Morning Herald.
"In fact, it resulted in just the opposite. Throughout Indonesia, Muslims, Hindus, Christians and Buddhists overwhelmingly condemned the attack and repudiated those who misused religion to carry out acts of violence.
"The entire nation galvanised to defend freedom, democracy and tolerance. And internationally, Indonesia became a key player in the fight against global terrorism." He added: "Indonesia also became an active proponent of interfaith co-operation."
Some 88 Australians were among the Bali dead, as well as 11 people from Hong Kong.
Gillard reiterated her intention to attend the memorial despite the possible terror threat which prompted Indonesia to declare its top security alert.
Gillard is due to give an address to remember the Australians who were among the victims of the strike on the Sari Club and Paddy's Bar on the tourist island's nightlife strip of Kuta.
Yudhoyono said the moment when the bombs went off would also be etched in the memories of Indonesians.
"The public debate over whether terrorism was a real or imagined threat to Indonesia was laid to rest," he said.
"We recognised that freedom, democracy and tolerance cannot be taken for granted. Our national security thinking evolved rapidly, and terrorism became public enemy number one."