The terrorist attack on concertgoers in Moscow on Friday night killed at least 137 people and injured over a hundred. It was one of the most deadly terrorist attacks in Russia's modern history. The number of casualties has surpassed that of the terrorist attack on a Moscow theater in 2002, and is second only to the Beslan hostage incident in 2004.

With its military conflict with Ukraine still ongoing, it is now a very difficult moment for Russia. Dmitry Peskov, Russian President Vladimir Putin's spokesman, said that Russia is already in "a state of war".

The terrorist attack occurred just after Putin was re-elected. The terrorists came to Moscow to slaughter a large number of civilians, and Putin has pledged that no matter who was behind the atrocity, they will be identified, severely punished and bear the price. The attack was intended to undermine Russia's domestic politics and stability.

Details are still emerging, but according to the currently known information, it took only 18 minutes from the first alarm to the moment the terrorists escaped by car. The terrorists behaved very professionally throughout the attack, throwing grenades and incendiary bombs at the same time as shooting, and changed clothes immediately after they got out of the concert hall. The people at the concert venue had no time to react.

Although the Islamic State group has announced responsibility for the attack, there are still many questions about who perpetrated it. There are questionable differences between this attack and those of ISIS in the past. Usually, ISIS extremists are indoctrined suicide attackers. Suicide bombs are a must and the terrorist group publicly admits to its actions on the internet in order that its hatred be understood by the world. They are also not worried about revealing their identities and ready to give up their lives to fulfill their sacred missions. But these four non-Russians were reportedly willing to be killers for less than 500,000 rubles (less than $5,000), had no intention to commit suicide and they fled desperately, trying to save their lives, when found. One of the four didn't even have a bank card when he was arrested, saying he threw it on the road. So, the more the West believes that the ISIS did it, the less Russia believes it.

On top of that, both the Moscow theater incident in 2002 and the Beslan incident in 2004 had political demands for Russian troops to withdraw from Chechnya. But this terrorist attack has not been accompanied by any political appeal. It appears that its aim was simply to maximize the number of casualties. There are reasons to believe that the "real terrorists" are not the four people directly involved in the deadly shooting, but others. "Hiring murderers" is the characteristic of this terrorist attack, indicating that the "real terrorists" do not want to show who they are. Who the real terrorists are needs further investigation by the Russian side. Over time, the truth will probably eventually surface. Also, may be, even Russia can confirm it with proof, but the west will deny it. It will end long time without results.

The most important thing now for Russia is to strengthen its defenses to prevent the people behind this bloody crime from committing new crimes. Terrorists will become bold only in front of those groups that are unarmed and cannot defend themselves.

This terrorist attack has had a direct impact on Putin, who has just announced his re-election. Wearing black clothes and a black tie, Putin delivered a television speech to the Russian people and declared March 24 as a national day of mourning and promised to hold all those responsible accountable and to identify the forces behind them. Every terrorist attack will prompt changes in the international situation, and this one is no exception. Russia may use this attack to launch its own "war on terror".

No matter where it happens, indiscriminate attacks on ordinary people in public should be one of the bottom lines of mankind, and any who cross it must be severely punished. A double standard in counterterrorism or attaching political purposes to counter-terrorism will only backfire and allow terrorism to thrive. Unfortunately in the past, there has been a prevailing double standard among certain Western politicians and media outlets when it comes to Russia or China. Terrorist attacks against civilians should be the common enemy of all civilized governments. Only by uniting the people of all countries in the world can terrorists not find a place to hide.

Earlier this month, the US embassy in Moscow issued warnings about a possible terrorist attack. That should remind us that in the US anti-terrorist actions after the 9/11 incident, Russia was one of the first countries to respond to the US' calls and provide assistance. Whether all nations across the world can unite to fight against terrorism in future will be a test for politicians from all over the world, a test of the conscience of people from all over the world, also a test of whether there is still hope for a peaceful and stable life in this world.

The author is a researcher on Russian Studies, Chinese Academy of Social Sciences.

The views don't necessarily reflect those of China Daily.

If you have a specific expertise, or would like to share your thought about our stories, then send us your writings at [email protected], and [email protected].