Most of the focus on ISIS is in the Middle East, where its worst atrocities occur and where it has seized territory the size of Austria.  At this point, the extent of an ISIS presence in South Asia is unclear.  Area intelligence agencies including India's Research and Analysis Wing (RAW) and Pakistan's Inter-Services Intelligence (ISI) dismiss the notion (at least publicly).  The chatter I have heard, however, is not about either of those countries, but about Bangladesh.

Although it is the third largest Muslim-majority country and the only country listed among the world's ten most populous and ten most densely populated, Bangladesh tends to get lost in discussions about South Asia.  As a result, radical Islamists along with a passive and sometimes sympathetic government have allowed some pretty nasty thing to happen there under the radar:

• After the initial allied operation in Afghanistan, Bangladesh became a haven for many fleeing al-Qaeda forces, who almost stole the country's aborted 2007 election.
• While posturing as "moderate," Bangladesh has had Islamists in its governing coalition, named roads and bridges after terrorist organizations, and persecuted journalists and authors with impunity.  I have defended two accused of "blasphemy."
• When I traveled the country at night, we were in constant communication with friends in the police who warned us which roads to avoid because they were controlled by Islamist terrorists.
• The current prime minister once admitted to a visiting French commander that the country has "anti-minority" laws.
• Minorities, especially Hindus, have faced constant attack.  Successive governments allow the ethnic cleansers to operate with impunity, and as a result, Hindus have been reduced from one in five to one in 15.
• Of late, several secular bloggers have been murdered brutally, with the murderers evading serious prosecution.

So I was not surprised when I was given the address of a house in the Bangladeshi capital of Dhaka alleged to be an ISIS headquarters, along with the name of an individual who I was told is its chief of operations.  ISIS has claimed responsibility for several murders in Bangladesh, and I was given independent confirmation about two ISIS killings: the murder of a blogger and publisher on October 30 and a policeman on November 4, both in the capital.  After the November 4 murder, ISIS circulated the following message on social media: "In a security operation, Allah enabled the soldiers of the state in Bangladesh to attack a police checkpoint… the soldiers of the caliphate withdrew safely."

Were these rogue actions, test messages, or part of a more coordinated effort already in place?

The significance of ISIS in South Asia could not be greater.  ISIS has demonstrated its ability to intimidate and motivate Muslims toward radicalism, and one in every four and a half Muslims lives in South Asia – more than four times as many Muslims as there are in the Middle East.  That a proclivity to radicalism in many areas already exists only makes ISIS's job easier.  Moreover, in the past several years, more and more Bangladeshi Muslims have told me that while they don't like the radicals, they no longer can rely on the U.S. for support.  "We don't know what Obama will do," one told me recently.  "We do know what the radicals will do."

In fact, it would be a mistake for the Obama administration not to recognize this possibly game-changing threat in its fight against ISIS.  Foreign policy vacillation, especially in soft Islamist targets like Bangladesh, has abetted the growth of Islamism.  To prevent ISIS from establishing itself in this population-rich area, the United States and the West need to act now: pressuring weak governments like the one in Bangladesh to cooperate, and adopting a far more robust foreign policy in semi-radicalized countries like Afghanistan and Pakistan.  We also need to recognize that among all the South Asian leaders, our greatest friend and ally in this struggle is Indian prime minister Narendra Modi, who already is battling a multi-front terrorist assault on his country.