AUDIE CORNISH, HOST:
ISIS isn't just a threat to Iraq and Syria. As the group spread across Iraq last summer and fall, neighboring Saudi Arabia started building a 600 mile fence aimed at keeping militants out. The Saudis are adding chain link razor wire fencing, silent alarms, watchtowers armed with video, along with thermal and night vision surveillance. Gregory Gause is head of the International Affairs Department at Texas A&M University's Bush School of Government and Public Service. I asked him if his high-tech barrier signals Saudi Arabia's fear of an outright invasion by ISIS.
GREGORY GAUSE: I think that that's one of those low probability but very high-impact events that governments tend to do over plan for. I think that the more serious issue for Saudi Arabia and many other states in the Middle East is the affect that ISIS can have within its own domestic populations. I think that there's quite a bit of sympathy in many areas of Saudi public opinion for ISIS' fight against the Assad regime, for their fight against what many people in Saudi Arabia see as an Iranian puppet-regime in Iraq. So there is undoubtedly sympathy for what ISIS is doing.
CORNISH: ISIS is linked to Sunni Muslims in identity. Saudi Arabia has traditionally been home to very conservative Sunni Muslims, and some have talked about private donors in the past funding or supporting the precursor to ISIS. Give us a context for why the Saudi government has been so aggressive about fighting ISIS.
GAUSE: Well, I think that they see ISIS as an analog to al-Qaeda. And the Saudis, in the 1980s, as we did, supported Islamist insurgency in Afghanistan against the Soviet Union and, in the '90s, kind of turned a blind eye to the development of this Salafi jihadist movement. And then that came back to bite them when al-Qaeda conducted a real campaign within Saudi Arabia against the regime. And I think that the leaders of Saudi Arabia see ISIS as possibly doing the same thing. And I think that there's a real recognition at that point in Riyadh that this could have really serious domestic repercussions for the country.
CORNISH: We've talked about this from the perspective of the Saudi government, but, when it comes to Saudi Arabia, what are the goals of ISIS?
GAUSE: Eventually they would like to take over Saudi Arabia, just like al-Qaeda wanted to. The holy cities of Mecca and Medina, the heartland of Arabia is almost irresistible to Salafi jihadists like ISIS. It is their home base. And so I think that there is a sense where ISIS is shooting at Saudi Arabia as an ultimate goal. But this particular attack, I think, was more just a shot across the bow to let the Saudi's know that, you know, you're in our sights.
CORNISH: We've been talking about this border fence, but what other actions is the government taking there in response to the threat that they perceive from ISIS?
GAUSE: At the beginning of 2014, the Saudi's officially put ISIS on their brand-new terrorist list. They criminalized any Saudi joining a foreign jihad. It's explicitly illegal for them to be members of ISIS or even express support for ISIS. So, in that regard, the Saudis defined ISIS as a domestic security threat. And that was, I think, the big escalation. There's also an effort on the part of the religious establishment at the behest of the Saudi government to try to delegitimize ISIS. That, of course, is a harder thing to do because, on the political front, it's easy for the Saudi religious authorities to say these guys are bad because they stand and against our government. But, at the practical level, the way ISIS governs the territory it controls is not all that different from - at least in theory - the way the Saudi religious establishment thinks Islam requires you to govern any territory. They work from the same texts, and although ISIS is much more extreme and much more brutal, there is a similarity in terms of the core texts that both the Saudi religious establishment and that ISIS looks at for guidance about how politics should work in an Islamic State.
CORNISH: Gregory Gause. He's the head of International Affairs at the Bush School of Government and Public Service at Texas A&M University. Thanks so much for explaining it to us.
GAUSE: It was my pleasure.