Sharing a border with impoverished Yemen, oil rich giant Saudi Arabia is becoming increasingly wary of its unruly neighbor, trying to prevent illegal immigrants and criminal gangs from using Yemen as a by-pass country to the Peninsula.
With Yemen still caught in the midst of a political and terror crises, with on the one hand al-Qaeda militants trying to tear down the fabric of society and on the other hand secessionist militias seeking to break up Yemen's territorial integrity, Saudi Arabia fears its neighbor is failing to adequately secure its 1.800 km joint border.
But if Saudi Arabia is legitimately worry that illegal immigrants and criminals of all sorts will try to use Yemen' spotty border control to their advantage, it is the threat posed by the Houthis (a Shiite rebel group based in the northern province of Sa'ada, situated directly south of the Saudi border) which has pushed Saudi officials to resume the construction of their border fence.
The idea is quiet simple; by sealing off Yemen completely, Saudi Arabia assumes it will be prevent local tribes from enacting their threat against the kingdom by taking up arms and attempting to expand their territorial influence right onto al-Saud's land.
It is important to note that Yemen and Saudi Arabia have a long history of border disputes.
Although former President Ali Abdullah Saleh signed in June 2000 with Saudi Arabia a border treaty, which aimed at putting to rest decades' old land disputes between the two nations, local tribes and groups, namely Aseer, a local NGO, have recently brought the matter of border demarkation back to the table, claiming Saudi Arabia is occupying Yemeni lands.
As in previous contestation, the provinces of Asir, Najran, and Jizan are at the heart of the matter.
Saudi border official Lt Col Hamed al-Ahmari told the BBC on Monday "Border security has dramatically worsened in the aftermath of the revolution, as thousands of illegal immigrants, drug smugglers and gun runners try to slip from impoverished Yemen into Saudi Arabia, one of the world's richest countries."
He explained the government was determined to fence off its southern border, all throughout its Red Sea coast in the west right up to Oman in the east.