“In this case, we underestimated ISIL and overestimated the fighting capability of the Iraqi army. ... I didn't see the collapse of the Iraqi security force in the north coming. I didn't see that,” the US spymaster was quoted by The Washington Post as saying.
The intelligence chief said the terrorist organization posed a long-term "strategic threat” to America, given "their actions and their statements about the inevitability of confrontation with the US."
Clapper’s comments reflect the divide within the US intelligence community about the dimensions of and the threat posed by ISIL.
Hours before US President Barack Obama laid out his “new strategy” for combating ISIL in a televised speech last Wednesday, one of his top counterterrorism advisers testified to Congress that ISIL had recruited an estimated 10,000 militants.
The next day the Central Intelligence Agency (CIA) released its assessment, saying the terror network could muster anywhere between 20,000 and 31,500 fighters across Iraq and Syria.
The United States and some of its regional allies, chief among them Saudi Arabia and Qatar, have been arming and training militant groups in Syria to fight the government of President Bashar al-Assad. Many of those militants have pledged allegiance to ISIL.
The US has renewed that policy with the Senate approving a measure Thursday to arm and equip “moderate” Syrian militants to fight against both ISIL and the Syrian government.
Obama has authorized airstrikes against ISIL targets in Iraq and Syria, but has ruled out American boots on the ground in a combat role.
This is while Obama has already deployed about 1,600 US Special Forces troops to Iraq to “advise” the Iraqi military.