NEW YORK/SYDNEY – On a day when the world was trying to comprehend the scale of the latest atrocity by the Islamic State in Iraq and Syria (ISIS), there were fresh reports from four different continents about a snowballing number of young people thronging to Syria to join the terrorist outfit.

New York was taken aback as reports emerged that two young men from Brooklyn were arrested on Wednesday for plotting to travel thousands of miles to fight under the ISIS banner.

Australia reported yesterday that around 110 of its residents had left to join the militants, including 30 or 40 women.

…As a means of countering the influence of ISIS, such measures would have limited impact, said Professor Rohan Gunaratna, terrorism expert from the S. Rajaratnam School of International Studies. He told The Straits Times: “Cancelling passports and withdrawing citizenships is not going to stop this wave. It could even lead to more home-grown attacks.