Since al-Qaida accords top priority to the "war against the US", disputes between/among religious sects were never its major concern. Al-Qaida's new leader Ayman al-Zawahri has even asked followers to avoid unnecessary clashes with other Muslim sects in order to protect the organization's "image" and save its limited resources. What al-Qaida has focused on is targeting US "agents" in Middle East and South Asia, namely the puppet governments such as the one led by Nouri al-Maliki in Iraq.

In contrast, expansion has been the driving force of the "ISIS" right since its birth. Apart from the Nouri al-Maliki government, which ironically is the least favorite of Washington, the Bashar al-Assad government in Syria, which is a real US "enemy", appeared to be the major target of most IS-led terrorist attacks. Even more absurd is the IS' brutal onslaught on Iraqi Yazidis, a Kurdish ethnic group which has nothing to do with the US-led Middle East order.

All this shows that the IS is hell-bent on redrawing the geopolitical map of the Middle East and creating a caliphate based on "pure Islam" in the region and beyond under the pretext of "war against the US".

Such "aspirations", if religious persecution can be called so, will serve as a magnet for terrorists and Islamic mercenaries across the globe. Compared with the al-Qaida's unrealizable "goal" of "defeating" Washington, the "aspirations" of the IS, built on the blood and suffering of innocents, seem within easier reach. That is why a number of Western extremists have preferred to join the ruthless IS rather than the al-Qaida.

To put it bluntly, members of al-Qaida are sheer terrorists, while those of the IS are a mix of terrorists, thugs, bandits and career mercenaries. So those living under the delusion that they are immune to "IS"-related troubles by assuming that the outfit is other countries' problem are simply kidding themselves. No place will be safe from the IS if countries across the world don't come together to end the menace.

The author is a researcher of the South Asian studies under the Chinese Academy of Social Sciences.