How many criteria are there for what is and what is not a terrorist attack?

US politicians use one criterion when they associate incidents, such as the fatal bombing in Boston, with terrorist groups. But when it comes to the killing of innocent residents by terrorists in China's Xinjiang and Tibet autonomous regions, it seems a different criterion applies.

When terrorists killed 24 innocent people, including two police officers, in Shanshan, Xijiang, on Wednesday, rather than showing sympathy to the victims and indignation toward the perpetrators, the US State Department spokesman urged China to "provide all Chinese citizens - including Uygurs - the due process protections to which they are entitled."

The spokesman even said, "The United States was deeply concerned by accounts of discrimination against Uygurs and other Muslims in China."

It seems that this spokesman was trying to claim the attack in Xinjiang was a clash between different ethnic groups. If we follow this logic, we could describe the killing of US citizens by terrorists as the clash of different civilizations.

Yes, the separatists, extremist and terrorist forces, which have launched terror attacks in Xinjiang, have their own political objectives, but so do other terrorist groups such as al-Qaida. But whatever their political objectives might be, it can never justify acts of terror.

The fact that 16 Uygurs died in the latest attack is strong evidence that the incident is anything but an ethnic conflict.

The cooperation of all countries will make a difference in the fight against terrorism worldwide. But such joint efforts need to be based on a correct understanding of what is terrorism.

The biased prism through which some US politicians view such horrible acts, means that if it happens in the United States or harms US citizens it is a terrorist attack, but when it happens in other countries it is viewed as something else.

We sincerely urge some US politicians to use reason rather than letting themselves be carried away by their bias on this question. Prejudice will only lead them away from the path that would allow them to reach the right conclusion. Which will do no good to the global fight against terrorism.