On 29 March, Egypts President Abdul Fattah al-Sisi announced that the member states of the Arab League are planning to form a joint military force to combat jihadist groups in the Middle East and North Africa. The announcement built on the momentum created by an unprecedented military intervention in Yemen by a Saudi-led coalition of Sunni militaries, and could be a defining moment in the history of the region.
The Yemen campaign, dubbed Resolute Storm, has to date taken in a series of air strikes on key military installations by the Saudi-led 10-nation coalition, and could see Egyptian boots on the ground in the Arab worlds poorest country within weeks. It is a more muscular approach to enforcing Riyadhs influence in the region with the backing of its allies, while pegging back its rivals. Those rivals include Sunni extremists such as Al-Qaeda in the Arabian Peninsula (AQAP) and Islamic State in Iraq and Syria (Isis), and Shia militias backed by the kingdoms main rival, Iran, including Yemens Houthi rebels.
Observers are already asking whether the intervention in Yemen has acted as a marker for the way the new Saudi monarch, King Salman bin Abdulaziz al-Saud, plans to define his time in power. An aggressive doctrine from the king would be a marked contrast to the quieter and more conciliatory tone of his predecessor, King Abdullah bin Abdulaziz al-Saud.
The Saudi-led coalition will help the tribes to take actions against Al-Qaeda in the Arabian Peninsula
Saud al-Sarhan, Saudi academic
For many, such an approach is long overdue, particularly given its galvanising effect on long-mooted plans for a pan-Arab military force and on cohesion among the Gulf states (all GCC members have pledged to back the Yemen campaign, with the exception of Oman). It is also seen as a break from a long history of allowing Washington to set the regions military agenda. Riyadh now looks keen to be viewed as a hard power in its own right, in part at least as a riposte to the decision by the White House to enter into talks over Irans nuclear programme.
But many questions remain as to how such an aggressive stance will work in the long term, and where the endgame for Arab interventions in the region might lie. The answers will be found in Yemen, with the new Saudi kings policy put to the test in the crucible of war.
Yemen is a melting pot of the kind of tensions that have wrought chaos elsewhere in the region. The country is already divided due to a Shia rebellion in the north, boiling secessionist sentiment in the south and a virulent Al-Qaeda franchise. It has been in freefall since inter-elite fighting sparked by popular unrest in 2011 led to the collapse of the regime of long-time president Ali Abdullah Saleh.
Until early 2015, Yemen had been undergoing a UN-overseen political transition due to end with the passage of a new constitution and fresh elections. The deal that helped set this in motion by getting Saleh to step down is known in Yemen as the GCC Initiative because of the role played by the Gulf states, Saudi Arabia in particular, to negotiate a truce between two warring factions that had previously formed the backbone of the Saleh regime.
Yemens current predicament has been caused by an odd partnership between Saleh and the Houthis, a Zaydi Shia militia that started out as a religious revivalist group and spent six years fighting Saleh in their northern highlands stronghold, the Sadah province.
Since early 2014, Houthi militias have been expanding their presence in the northwest of the country, putting down the conservative Sunni Islamist faction that broke from the former presidents regime in 2011, backed by tribes and military units still loyal to Saleh.
In September 2014, the Houthis took the capital, Sanaa, before forcing a peace deal on favourable terms with Abd Rabbu Mansour al-Hadi, Salehs former vice-president, who took the reins after Saleh stepped down in 2011 as part of the GCC deal. In 2012, Al-Hadi was made president in a one-candidate election.
In January this year, the Houthis, enraged by what they saw as a plot by Al-Hadi to quickly pass a new constitution that would enshrine a system of federal government the northern rebels oppose, first kidnapped the presidents chief of staff and then besieged his Sanaa residence, placing him under house arrest. Al-Hadi resigned in protest, but rescinded his resignation a month later when he fled to the southern port town of Aden. The UN envoy to Yemen, Jamal Benomar, stepped up his attempts to prevent civil war by mediating a peace deal between Al-Hadi, the Houthis and Yemens main power brokers.
For support, Al-Hadi turned to Riyadh, which had already propped up his presidency with $4bn of cash and fuel shipments. He implored the Saudis to underwrite what was in effect a government in exile within Yemen itself, and to help arm and pay for a 20,000-strong militia to push the Houthis out of Sanaa. Riyadh, which has decided the group must be put down at any cost, responded in kind.
But it soon became clear the well-equipped and militarily experienced Houthi-Saleh alliance would be able to outgun the ragtag bunch of soldiers, tribesmen and Islamists Al-Hadi had rushed to cobble together. After naming Aden his temporary capital, the president fled it in late March as Houthi militias and Saleh loyalist military units closed in and the air force dropped bombs near the presidential palace.
With Al-Hadi fleeing a second capital in as many months, it became clear to Riyadh that he would not be able to topple the Houthis on his own terms. The Saudis would have to push the Houthis out themselves. The Houthis ties with Iran were becoming increasingly evident as Tehran promised to supply them with oil for a year and started twice-daily flights into Sanaa after Al-Hadi fled to Aden. Allowing the rebels to consolidate their control over a country the Saudis see as their own backyard was simply unacceptable to the kingdoms leaders, according to a Western diplomatic source who regularly visits with policymakers in Riyadh.
It is hard to know whether or not the ascension of King Salman to the Saudi throne on 23 January, and his decision to appoint his son, Prince Mohammed, to the key post of defence minister, prompted a more aggressive approach to Yemen, or if the collapse of the Al-Hadi-led resistance would have forced Riyadhs hand either way. But the response to the Houthis latest advance has been shocking in its swiftness.
Al-Hadi was still attempting to escape Yemen when the first air raids were launched early in the morning of 26 March. By the time the Arab League meeting was held in Egypt two days later, a newfound unity was unfolding. Al-Sisi and King Salman promised to back the Yemen campaign to the hilt.
The question remains what the endgame in Yemen will be. Cairo and Riyadh say they will accept nothing less than unconditional surrender from the Houthis. But the Houthis wont stop even if the military is used, says Farea al-Muslimi, a Sanaa-based political analyst. They have their plan and they will stick to it.
If that is the case, then it is likely a ground invasion will be required if the Saudi coalitions goals of a Houthi surrender and the reinstatement of Al-Hadi are to be met.
Given the last remnants of Yemens armed forces are Saleh loyalists and are currently being pummelled by the coalitions airstrikes, an invasion could quickly metastasise into an occupation. This would be plagued by a renewed Houthi insurgency and attacks from AQAP, which is already benefiting from the power and security vacuum caused by the current situation and from rising sectarian anti-Houthi sentiment among the countrys majority Sunni population.
The target of the Saudi-led coalition is the Houthis and not the Yemeni army, says Saud al-Sarhan, a Saudi academic, who argues that the Saudi intervention in Yemen will be a success. Any Yemeni military installations targeted are those, as I believe, that have been overrun by the Houthis. It should be noted only certain elements of the Yemeni armed forces have deserted to join the Houthi-Saleh forces, and there remains an army loyal to the state.
Of the dangers of Saudi Arabia and its allies becoming an occupying force bogged down in internecine conflicts, Al-Sarhan says Riyadh is aware of the American mistake of destroying the Iraqi army in 2003. The kingdom can play a role in mobilising Yemens tribes against the Houthis to reduce the appeal of AQAP.
AQAP benefits from the Saleh-Houthi alliance because the Houthi aggression helped AQAP to make an alliance with the tribes, says Al-Sarhan. The Saudi-led coalition will help the tribes to take actions against AQAP.
The problem is that even the best-laid plans can go awry. Militaries that take part in ground invasions often have to adapt to the shift from offensive force to occupying power with a growing list of responsibilities for which they are ill-equipped to provide. King Salmans doctrine, if that is indeed what the region is witnessing, has the potential to mark a major shift in the history of the region. But only time will tell whether that shift is a positive one. Yemen will prove the litmus test.