ISIS 'number one threat' to US, warns Pentagon

The increasing involvement of foreign fighters in the ISIS is a major concern for US

The spread of militant outfit, ISIS, in Iraq and Syria, is winning the group new recruits from Europe and America. The size and reach of the group has now led the United States to place the threat posed by the organization on par with the ones based in Yemen.

According to The Washington Times, Michael Vickers, the Pentagon's Under Secretary for Defense Intelligence, said at the Aspen Security Forum on Thursday that Syria is the number one threat to the American homeland right now.

One of the prime factors that is being looked at as a serious threat by the US is the increasing involvement of foreign fighters in the ISIS.

John Carlin, the assistant attorney general for national security at the Justice Department, said that the number of such fighters within the outfit is unprecedented, more than the ungoverned spaces in Pakistan and Afghanistan and it poses a serious threat because a significant percentage of these people are American passport-holders.