Saudi Arabia is nervous about ISIS. According to The Guardian, the entire country is on the alert for jihadi activity ever since a general and two other soldiers were killed by a suicide bomber earlier this month. The attack was the first deadly assault along the country's border with Iraq since it joined the US-led coalition fighting the Islamic State.

The Guardian reports that Saudi Arabia has been widely criticized in the past for helping ISIS' rise by funding Islamist groups fighting to overthrow Syria's president, Bashar al-Assad. However, in recent months it has imposed stricter controls and criminalized fighting abroad, and has rejected accusations that it supports terrorism. 

Now, it is doing its best to disassociate itself from ISIS altogether - a 600-mile wall is being constructed in order to separate the country from Iraq to the north. Business Insider reports that the proposal of such an effort was made in 2006, but work only began in September of last year after the Islamic State acquired a substantial land border with Saudi Arabia to the south.

The wall itself is to be a combination of a wall and a ditch, and its border zone includes five layers of fencing with watch towers, night-vision cameras, and radar cameras. Furthermore, Riyadh also sent an extra 30,000 troops to the area.

NPR recently interviewed Gregory Gause, who is head of the International Affairs Department at Texas A&M University's Bush School of Government and Public Service. When asked about ISIS' intentions in Saudi Arabia, he stated, "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."

He continued, "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."