Unprecedented both in scale and for the speed of its spread, the so-called "Arab Spring" movement has resulted in surprise political change in countries including Egypt and Tunisia this year, and also fostered continued unrest in others, such as Syria.
But the regional transformation of 2011 will perhaps be most readily remembered for the end of Col Muammar Gaddafi's more than 40-year tenure as Libya's leader.
Uniquely among the transitions of power seen this year, the activity which resulted in Gaddafi's fall was the result of a popular uprising, running in parallel to a multinational mission mandated by the UN and requested by the League of Arab Nations. While early strikes made against regime targets threatening Libyan civilians were made by the armed forces of leading players such as France, the UK and the USA, ownership for the campaign was transferred to NATO control on 31 March, under operation 'Unified Protector'.
As with previous campaigns run by the alliance, contributions and commitments varied considerably between its 28 member states and Partnership for Peace nations. But, in a new dynamic, the Libyan mission also saw three Arab nations involved. Qatar and the United Arab Emirates went as far as making combat aircraft available to enforce a no-fly zone and also perform some strike tasks.
Summing up the support received from these partners, following the Libyan National Transitional Council's declaration of liberation on 23 October, Unified Protector commander Lt Gen Charles Bouchard hailed the role played by the Arab partners. He said: "They provided assistance in plans and in targeting. Some of them completed air activities, be it air patrolling or provision or bombing missions in the area. But throughout, to me, the best advice was the knowledge of the culture and their advice to me as to how to continue with this mission and how to interpret what we saw on the ground."
Details of the precise activities performed by the Gulf nations has not been disclosed, but the UAE is known to have performed a number of strikes against targets using precision-guided weapons carried by its Lockheed Martin F-16E/F Block 60 combat aircraft. An operational update provided by the UK Royal Air Force in mid-July revealed that 100% of the UAE's weapons releases had been against pre-planned or fixed targets.
Originally deployed to Decimomannu air base in Sardinia, the F-16s were accompanied by a detachment of six Dassault Mirage 2000-9 fighters. The UAE's contribution represented just part of its formidable inventory, which Flightglobal's MiliCAS database lists as including an active fleet of 78 F-16E/Fs, delivered between 2003 and 2007. While these are potentially the most sophisticated examples of the classic fighter currently flying worldwide, the operator has a long-held interest in acquiring a more modern type, most likely Dassault's multi-role Rafale. Working in close concert with the French air force from Sigonella, Sicily, Qatar's Mirage 2000-5s were assigned to support the air policing mission (below). This ultimately "non-kinetic" commitment was also met by fighters from several other nations, while others delivered much-needed reconnaissance services.
© French air force
"The no-fly zone was a balance between deterrence and actions," Bouchard says. "We ensured that approved non-NATO flight activities remained unimpeded and in many ways ensured that the humanitarian assistance flow would continue." But denoting the unprecedented demands and also the range from home of their action, both Gulf air forces encountered some difficulties. Several of Qatar's aircraft had to make an emergency diversion to Luqa airport in Malta after running short of fuel during their deployment to the Mediterranean, and one of the UAE's F-16s was destroyed in a crash after over-shooting the runway at Sigonella.
For the Libyan Arab Air Force the outcome of the campaign was far worse, however, with much of Gaddafi's assets having been destroyed or kept out of action due to the threat of facing a superior adversary. Several combat aircraft - in the hands of both loyalists and rebels - had been shot down during initial hostilities between the Libyan regime and opposition forces, and a French air force Rafale destroyed a Soko G-2 Galeb trainer on the ground after it had breached the terms of the no-fly zone in late March.
Few aircraft escaped destruction or capture, with the high-profile exception of two armed Mirage F1s which landed in Malta on 21 February after their pilots defected. One of the aircraft was pictured sporting new Libyan markings at an air show on the island in late September.
Flight International's World Air Forces directory for 2010-11 listed Libya as having almost 380 aircraft in its inventory, including combat types the Mirage F1, Mikoyan MiG-21 and MiG-23 and Sukhoi Su-22 and Su-24. Images have shown several of these, including MiG-23s, destroyed on the ground, and the operational status of other assets is unclear.
© Rex Features
Many of Libya's combat aircraft were destroyed, like this MiG-23
As seen previously in Iraq and Afghanistan, the process of replacing domestic military power will be a gradual process, and most likely started by providing training for ground forces to establish and maintain security. New aircraft arrivals are unlikely for some time, but typically start with assets such as utility helicopters and transport aircraft, before moving on to systems such as turboprop and jet trainers and eventually combat aircraft. However, Libya already had six Yakovlev Yak-130 trainers on order, according to MiliCAS.
NATO was due to end its air campaign on 31 October, after a period of seven months. With the alliance stepping down its military activities, the responsibility for supporting the political change in Libya rests with the UN.
"We have fully complied with the historic mandate of the UN to protect the people of Libya, to enforce the no-fly zone and the arms embargo," said NATO secretary general Anders Fogh Rasmussen. "Operation Unified Protector is one of the most successful in NATO history."
By 23 October, coalition aircraft had flown more than 26,300 sorties during the NATO campaign, with almost 9,660 of these concerned with identifying or engaging targets. As well as providing a test for their aircraft fleets, the commitment validated the recent investments made by Gulf states in supporting assets, such as transport aircraft.
Qatar employed its new Boeing C-17 strategic transports during the deployment of its Mirage force, with this task following its use of the type to deliver relief supplies to earthquake-hit Haiti early this year. Its capabilities will soon be further enhanced through the arrival of four Lockheed Martin C-130J tactical transports, recently accepted in the USA. The UAE, meanwhile, has received at least two of its C-17s from a six-unit order.
Currently lacking air-to-air refuelling aircraft, the UAE will gain this key capability with the Airbus Military A330 multi-role tanker transport from next year, with three of the type to join its fleet. Through such investments, its air force will be able to play an equal or potentially greater part in future allied operations.