Australian Foreign Minister Julie Bishop in May. (Jeon Heon-Kyun/European Pressphoto Agency)

The Islamic State has often been underestimated. Sure, it created terrifying execution videos. But it seemed unlikely the group would chalk up its recent stunning territorial gains in the face of coalition airstrikes.

And when it came to the Islamic State developing anything resembling weapons of mass destruction? No way.

[Islamic State ‘moron’ bragging online brings an airstrike on himself]

“In short, [the Islamic State] does seem interested in acquiring chemical, biological, and nuclear weapons, but ambitions do not necessarily equate with reality,” Dina Esfandiary and Matthew Cottee of the International Institute for Strategic Studies wrote in “The very small Islamic State WMD threat,” published in Bulletin of the Atomic Scientists last year. “The complexities of such weapons, combined with the difficulties involved in obtaining and handling the necessary material, make the likelihood of its use remote. Let’s not exaggerate the threat.”

But now, a senior official for one of the United States’s closest allies in the battle against the Islamic State has warned the jihadist group might have WMDs after all. Julie Bishop, Australia’s minister for foreign affairs, said the Islamic State was already wielding chemical weapons.

“The use of chlorine by Da’ish, and its recruitment of highly technically trained professionals, including from the West, have revealed far more seriou­s efforts in chemical weapons development,” Bishop said, using an alternate name for the Islamic State in a speech reported by the Australian. She did not specify the source of her information.  “… Da’ish is likely to have amongst its tens of thousands of recruits the technical expertise necessary to further refine precursor materials and build chemical weapons.”

Reports of Islamic State chlorine attacks surfaced as early as last year, but remain either unconfirmed or tentatively reported on by mainstream media sources.

[Islamic State militants allegedly used chlorine gas against Iraqi security forces]

Bishop said that the Islamic State will stop at nothing to challenge sovereign governments and international order in its attempts to create a caliphate.

“They seek to undermine and overthrow that order — and as we have seen, are prepared to use any and all means, any and all forms of violence they can think of to advance their demented cause,” Bishop said. “That includes use of chemical weapons.”

Bishop’s comments came in an address to the Australia Group, a coalition of 40 countries including the United States that seeks to limit the spread of chemical and biological weapons. Though her comments did not address nuclear weapons, Bishop told the Australian in a follow-up interview that NATO was concerned about the theft of radioactive material.

“The insurgents did not just clear out the cash from local banks,” she said. “… That’s why stopping Da’ish gaining territory is so ­important.”

Without naming the Islamic State, NATO did warn of nuclear proliferation in April.

“NATO’s Strategic Concept made clear that the proliferation of nuclear weapons and other weapons of mass destruction (WMD), and their delivery systems, could have incalculable consequences for global stability and prosperity,” the organization said in a discussion of weapons of mass destruction on its Web site. “During the next decade, proliferation will be most acute in some of the world’s most volatile regions.”