TEMPO.CO, Jakarta - Opposing the Islamic State in Iraq and Syria (ISIS) which has morphed into the Islamic State (IS) does not mean opposing Islam. What needs to be resisted is the violence they carry out to perpetuate their beliefs. This is why the government must actively prevent them from luring citizens into their movement. Allowing them to grow in this country is like breeding a new kind of terrorism.

The need for vigilance is urgent. On June 29, ISIS declared an Islamic caliphate in the country. Militant groups in Indonesia declared their oath of loyalty to Abu Bakar Al-Baghdadi, leader of IS. Among those who took the oath were Abu Bakar Ba'asyir and a number of convicted terrorists in jail. Some are convinced Al-Baghdadi can replace Al-Qaeda and Osama bin Laden. In fact, some are convinced that Al-Baghdadi is of higher stature than bin Laden because he is regarded as a khalifah, the highest Islamic leader.

We cannot penalize people for their thoughts, their knowledge or their beliefs. But we must be very vigilant because taking oath is the crystallization of radicalism, in fact, of terrorism. By vowing loyalty to IS and to the 'khalifah' Al-Baghdadi, means believing that Indonesia is a kafir (non-believer) state that must be fought against. According to the khalifah, other such states must be opposed until they bow to the khalifah.

Admittedly, terror acts by IS in Indonesia have not happened yet. IS seems to be focusing on solidifying their presence in Iraq and Syria. What is worrying, however, is information that 50 Indonesian nationals claiming to be IS followers have flown to Iraq and Syria to wage war. Some of them, like Abdul Rauf, who was convicted of the Bali bombing, have been killed.

The involvement of Indonesians is clearly a legal violation. The Penal Code forbids the participation of Indonesians in rebellions taking place in friendly countries. Enlisting in a foreign army can also lead them to lose their citizenship, in accordance with Article 23 of Law No. 12/2006.

Those who have gone to Iraq and Syria could well come back to spread radicalism and terrorism in Indonesia. After all, we have had such a precedence, involving the alumni of the war in Afghanistan. One of them was Umar Patek, who later became the mastermind of the first Bali bombing in 2002.

The government should be more active in keeping an eye on them, including former terrorism convicts who seem to have taken part in the activities. Demonstrations by ISIS followers with their black flag should not be allowed. The government must move fast, because the spread of this movement through social media can have devastating consequences.

Prevention measures can be carried out, for example, through education. There must be an understanding of the true not radical meaning of religion, especially among the youth. This is important because the seeds of radicalism have begun to be smuggled in, aimed at school and university students. As an example, oath-taking rituals were held at a room inside the Syarif Hidayatullah State Islamic University, at the start of this month. But the campus authorities claimed that the organizers only rented the space and denied the students' involvement.

The government must immediately declare ISIS to be an outlaw organization. As such, law enforcement agencies can begin to act against those involved. (*)