These are worrying times for Saudi Arabia and Yemen. The rugged terrain and porous border between the two countries augurs ill for these neighbouring countries, one an oil-rich kingdom and the other an impoverished mountain nation. Al-Qaeda and affiliated Islamist terrorist groups are operating freely on both sides of the border. The Saudis have long found it difficult to police the 1,800 km border with Yemen, and last week's terrorist attack occurred in Shahrourah in the vicinity of the Wadia border post with the Yemeni province of Hadramout. A panoply of regulations is now being introduced that should make it harder for Al-Qaeda to launch terrorist attacks in Saudi Arabia and Yemen. There is also the risk that vulnerable groups in Saudi Arabia's least-developed regions may now be driven into the arms of Al-Qaeda, and calls for joining militant terrorist groups have sometimes fallen on fertile ground. While the latest attack was a challenge to Saudi security, the Saudi authorities might argue that this was not quite the setback to the security of the kingdom that it seemed. But the approach of the Saudi authorities to security policy has not pleased everyone in the Arabian Peninsula. The ramifications of the border-post attack could destabilise the border region between Saudi Arabia and Yemen. Al-Qaeda in the Arabian Peninsula has claimed responsibility for the attack, and as Al-Ahram Weekly went to press it appeared that the attack had killed ten people, including five Saudi security officers. Meanwhile, the ongoing conflict in Amran in the north of Yemen will determine the future shape of Yemen, and those taking part in the conflict have been fighting over power in this part of the country for more than 50 years. All political and religious rivals, including Al-Qaeda, are linked in one way or another to this complicated conflict, continuing in recent weeks with hundreds being killed or injured on both sides. Hundreds of families have been displaced from Amran City, where militants are fighting from street to street. Amran is the centre of the Hashed tribe, Yemen's most influential, and home of the Ahmar family that leads the Hashed. The Ahmar family also leads the largest Sunni Islamist party in Yemen, Al-Islah, the Yemen Muslim Brotherhood. This year, for the first time in the history of the Hashed Shia Houthi militants and tribesmen from the Bakil, the second most influential tribe in Yemen, attacked and destroyed the palace of the Ahmar family in Amran, ending its leadership and domination over the Hashed. This conflict has tribal, sectarian and political dimensions, as the Houthi movement built its strength and popularity after winning six wars against government troops from 2004 to 2010. Both the Houthi and Al-Islah rose up against former Yemeni president Ali Abdullah Saleh during the Arab Spring, who had been using them against each other during his 33 years in power. With Saleh now gone, Al-Islah and Houthi are fighting each other for power in the country, Saleh's supporters in Amran and elsewhere sympathising with the Houthis as they do not like the Muslim Brotherhood. Al-Islah is trying to convince the army to fight against the Houthi. However, the army's 310 Brigade, based on a hill overlooking Amran, is commanded by Hamid Kushaibi, a general close to Al-Islah. The Houthis say that Al-Islah activists call them kafir (infidels) and refuse coexistence with them. Last week, the leader of the Houthi militants, Abdel-Malik Al-Houthi said on the group's TV station Al-Masirah that advisor to current Yemeni President Abd-Rabbuh Mansour Hadi for defence and security Ali Mohsen had given missiles to Al-Qaeda in Arhab near to Amran for it to use against Houthi fighters. Al-Houthi himself wants Amran to be under his control, or at least under the control of the neutral local government, and not of his enemies as it is the case now. He has demanded that the current local government, including its military and security commanders, be replaced by one from the south. However, Al-Islah has refused such demands and the conflict has continued. Observers say that the Houthis aim for more than taking control of Amran. “The most violent battle will be to control Sanaa, as the Houthis want to expand towards the south of Sanaa and beyond,” said Najeeb Ghallab, a politics professor at Sanaa University. The Ahmar family is also doing its best to take revenge on the Houthis. “The Ahmar are feeding the sectarian conflict to take revenge on the Houthis, who humiliated them and dismissed them from their palace in Amran,” said Ghallab. On 6 July, a representative of Al-Islah refused to attend a meeting of the mediation committee between the two sides, saying that the government was siding with the Houthis. Al-Islah wants the government to declare war against the Houthis, with its media accusing the minister of defence of helping the Houthis. However, the minister, Mohamed Nasser Ahmed, has said that he wants both groups of militants to surrender their weapons to the state. The conflict intensified on Sunday, when Houthi fighters started to shell the 310 Brigade and tried to plunder military equipment and supply goods from Sanaa. About 200 people including women and children were killed or injured in street-to-street battles inside Amran. Al-Qaeda and the Houthis are enemies, and the Houthis accuse the Brotherhood-affiliated Al-Islah of using Al-Qaeda against them. “Al-Qaeda has carried out tens of operations, including car bombs, in Houthi-controlled areas like Sadaa, Jawf, Amran and Hajja,” said Abdel-Razzak Jamal, an expert on Al-Qaeda affairs in Yemen. “But I do not think the Brotherhood is using Al-Qaeda, though it is using tribesmen to strike the Houthis in these areas,” Jamal added. The debate about how to contain the threat posed by Al-Qaeda in the Arabian Peninsula is not settled. There is insufficient coordination between the two neighbours of Saudi Arabia and Yemen, and this has been exacerbated by the income inequality between the Peninsula's economic powerhouse and one of its richest nations and the poorest country in exacerbating tensions in the region.