ISIS will be in position to get nuclear weapons if allowed to consolidate power ...

REUTERS

The risk of a terrorist attack using nuclear or chemical weapons has just gone up.

ISIS is willing to kill large numbers of innocents, and it has added three capabilities that catapult the threat beyond anything seen before: control of large, urban territories, huge amounts of cash, and a global network of recruits.

British Home Secretary Theresa May warned that if ISIS consolidates its control over the land it occupies, 'We will see the world's first truly terrorist state' with 'the space to plot attacks against us.'

Its seizure of banks and oil fields gave it more than $2 billion in assets. If ISIS could make the right connection to corrupt officials in Russia or Pakistan, the group might be able to buy enough highly enriched uranium (about 50 pounds) and the technical help to build a crude nuclear device. Militants recruited from Europe or America could help smuggle it into their home nations.

Or ISIS could try to build a 'dirty bomb,' conventional explosives like dynamite laced with highly radioactive materials. The blast would not kill many directly, but it would force the evacuation of tens of square blocks contaminated with radioactive particles.

The terror and economic consequences of a bomb detonated in the financial districts of London or New York would be enormous.

ISIS could also try to get chemical weapons, such as deadly nerve gases or mustard gas. Fortunately, the most likely source of these terror weapons was just eliminated.

The Obama administration struck a deal with Syrian President Bashar Assad that has now destroyed the 1,300 tons of chemical bombs Assad built. Without this deal, ISIS would likely already have these weapons.

There are two good answers to these threats. First, drain the swamp: Secure or eliminate the materials ISIS would need to build terror bombs. Second, deter any attack by making sure ISIS knows our retribution would be swift, certain and devastating.

Joe Cirincione is president of Ploughshares Fund, a global security foundation, and author of 'Nuclear Nightmares: Securing the World Before It Is Too Late.'