Lessons to be learned from lone wolf attack

He had earlier been investigated, twice, for suspected connections with terrorists.

He called 911 and pledged allegiance to the Islamic State group.

And IS claimed responsibility for the attack immediately afterwards.

Yet it will take credible evidence to prove Omar Mateen, who carried out the deadliest mass shooting in United States' history in Orlando, Florida, was truly associated with the terrorist group.

While the FBI works its way into that riddle, a number of long-standing controversies have regained the limelight: gun control; gay, lesbian, bisexual, and transgender rights; and, of course, the US approach to combating the IS.

Finding out if the killer was an Islamic jihadist, as he claimed, or hated homosexuals, as his father indicated, matters, because homophobia and homegrown terrorism have very different meanings to a society and entail dramatically distinct solutions. And underestimating the threat of the IS on US home soil may result in greater security risks.

Even before a definitive assessment of the killer's motivation, however, there are two things that are worth vigilance.

One is the IS's pernicious impact. Mateen may or may not have had connections with the jihadists. But his claim of allegiance to them, along with his previous record of "extremist" utterances showed the terrorist group has an audience that is difficult to locate and identify.

The IS group is adept at using social media and the internet to spread its extremist ideology and hatred, recruit jihadists and order attacks. If the Orlando attack highlights the need to deal with online terrorist communication, it would be conducive to international collaboration in the fight against terrorism worldwide.

US President Barack Obama described the killer as "a person filled with hate". That leads us to the other lesson to learn from Orlando: The havoc an individual can cause.

China has its own experiences showing that it does not take a full-fledged terrorist to create a sense of fear, or harm innocent people. On Sunday, a man tried to kill himself after injuring four others with a homemade bomb at Shanghai airport. There have been multiple reports of disgruntled individuals targeting public transport vehicles, mostly crowded buses, in order to have their alleged "injustices" noticed.

Lone wolf attacks like these may be very difficult to monitor or prevent. But such tragedies do raise the question of how to reduce the likelihood for troubled, angry members of society to make a statement in the form of violence.