There are three possible outcomes to the war in Yemen: reconstruction as a single state, partition into two states – north and south – or fragmentation into multiple statelets. Of these, only a single state can offer some hope of a more secure future for the Yemeni people but the prospects for achieving it look increasingly slim and the balance of probabilities points towards fragmentation.

Throughout most of its history Yemen has lacked the kind of single, centralised control that would qualify it to be described as a unified state. Pre-Islamic texts speak of “al-Yamanah”, a kingdom which undoubtedly lay within modern Yemen but probably comprised only a small part of it and, regardless of who ruled the principal cities, the mountainous terrain and the remoteness of many villages allowed numerous fiefdoms of varying size and importance to flourish. 

Unification of north and south

The modern Republic of Yemen is a recent creation, brought about in 1990 by unification of the Marxist-run People's Democratic Republic of Yemen in the south and the traditionalist Yemen Arab Republic in the north. Though much celebrated by Yemenis at the time, the hasty wedding did not lead to a happy marriage.

Unification also brought multi-party democracy (at least on paper) and in 1993 Yemen became the first country in the Arabian peninsula to hold competitive elections under universal suffrage. But Yemeni democracy turned into a way of institutionalising differences rather than resolving them, and in the meantime Ali Abdullah Saleh, who had presided over the north since 1978, consolidated his strength.

Saleh's power was far from absolute, however. Central government remained weak and its writ barely extended beyond the major cities. In rural areas, customary (tribal) law usually took precedence over state law. Tribal militias – some of them heavily armed – at times proved more than a match for the national army. 

Faced with numerous unruly or disaffected elements, Saleh played them off, one against another, using a mixture of persuasion, bribery and force to keep himself on top – a process he once described as "dancing on the heads of snakes". 
But Saleh's snake-dancing skills eventually began to fail him. Between 2004 and 2010 the regime fought six intermittent wars with Houthi rebels in the north but was unable to quell them. Meanwhile in the south, separatist sentiment was growing. Then, in 2011, the Arab Spring arrived and vast numbers of Yemenis took to the streets demanding that Saleh step down.

After much resistance, Saleh resigned in 2012 and Yemen embarked on a UN-approved "transition" process. Hopes for an orderly transition collapsed when the Houthis, supported by their former enemy Saleh, over-ran much of the country, including Sanaa, the capital – thus triggering military intervention by the Saudi-led coalition.

Ceasefire – and then what?

With the war now in its third year, and with an ever-worsening humanitarian situation inside Yemen, the need to call a halt is obvious. That would be a start but it is not a solution, as Anthony Cordesman points out:

"No ceasefire or settlement that leaves a weak, ineffective, and divided government in power can end Yemen’s humanitarian crisis or allow it to move forward.
"Real peace and stability can only come if Yemen can reach a level of unity it has lacked in the past, create a modern enough central government to actually focus on recovery and development, and attract major levels of outside aid."

The need, then, is for something never achieved in Yemen's recent history: government that is relatively free from corruption and nepotism; government that treats people equitably and does not maintain power through patronage; government that commands respect from the vast majority of Yemenis and inspires confidence among investors and aid donors. It's a very tall order, but without it there will be more armed conflicts sooner or later.

'The United States of Yemen'

Before war broke out, Yemen had been on the point of turning into a federal state comprising six regions – two in the south and four in the more populous north. The "United States of Yemen", as some dubbed it, was seen as the best hope for preserving national unity. Redistributing power to the regions was partly a defence against separatist activism but also a reaction to the inadequacies of central government under Saleh's rule. 

The federal plan was not without merits. It could, in theory, make government more responsive to regional and local needs. In Yemen's case, though, several factors mean that federalism – far from holding the country together – is likely to weaken national government even more and increase the likelihood of fragmentation.

One problem is uneven distribution of people and resources. As currently conceived, the federal region of Hadhramaut, in south-eastern Yemen, accounts for about 50% of the country's land mass, 80% of its oil production and only 10% of its population. That gives the inhabitants a strong incentive to claim the region's mineral wealth for themselves rather than sharing it with the rest of the country; it almost invites them to launch a struggle for secession.

Federalism will accelerate the country's break-up unless there is also a central government in Sanaa which has enough authority to arbitrate between regions and is capable of imposing its will when necessary, in ways that Yemenis can recognise as just and fair.
Oil is not the only issue that needs to be tackled nationally. The presence of al-Qaeda is another, as is Yemen's looming water crisis. In the book, Why Yemen Matters, Helen Lackner writes:

"Without effective water governance and management … Yemen’s long-term perspective is one of worsening poverty, and therefore of further deterioration of security and safety. Sooner rather than later, this is likely to lead to civil strife on an unprecedented scale … 
"The state must retain final authority over water management and enforce decisions that protect the interests of all Yemenis, rather than bowing to political pressure from powerful interest groups."

The north-south divide

In addition to the centrifugal tendencies reflected by federalism there are also demands in the south for full-blown independence. The Southern Movement (al-Hirak) is engaged in one of the world's oddest "liberation" struggles: it seeks to re-establish a vanished state which was the accidental product of British and Turkish imperialism.

When the British withdrew from Aden in 1967, the southern part of Yemen became the Arab world's first (and last) Marxist state. The People's Democratic Republic of Yemen survived in the south for 23 years before unification with the north.

Since the 1960s, aspirations towards national unity had been part of the political rhetoric on both sides of the divide, but for most of the time it was mainly rhetoric. Talking of unity without actually achieving it was one way of managing relations between north and south, while each side continued building its own separate state: 

The root of the problem was that ultimately Yemeni nationalism could not be reconciled with the existence of two separate regimes. This presented the governments of north and south with a serious logical and practical difficulty. They were obliged to espouse unification as a long-term goal, since to do otherwise would appear unpatriotic and damage their claim to legitimacy. On the other hand, they wanted to ensure their own survival and were aware that actual unification could easily prove suicidal for either or both of them. 

To mitigate the illogicality of their position, both sides claimed to be the true representative of Yemeni nationalism; the south, for instance, changed its name from People’s Republic of South Yemen to People’s Democratic Republic of Yemen – omitting the word “south” – in what has been described as “an open claim to the whole of Yemen under the banner of socialism”. 

Such claims merely introduced a further illogicality by obliging each regime to challenge the sovereignty of the other and meant that the normal principle of non-interference in another state’s internal affairs did not apply. While discussing co-operation, both regimes were supporting each other’s internal opponents, either to put pressure on the other regime or in the hope of overthrowing it. The reasoning behind this was that unification would be easier if a more sympathetic government came to power on the other side. 
In addition, uncertainty as to the means for achieving unification meant that both sides pursued it in different and often incompatible ways. At a government-to-government level, negotiation alternated with confrontation, sometimes at astonishing speed. Hence, the two wars of 1972 and 1979 were followed immediately by unity agreements which later fell by the wayside.

Unification came about in 1990 mainly because the south faced a dire situation, both economically and politically. In 1986 political in-fighting led to a bloodbath which more or less finished off the PDRY as an independent country. When the shooting stopped, 70% of the Socialist Party's central committee were gone – dead, arrested or in exile – and this tipped the balance in the north's favour.

Soviet support for the PDRY was also declining and southern leaders became increasingly alarmed by the collapse of Communism in eastern Europe. They became especially worried after the 1989 revolution in Romania, fearing they might meet the same fate as the toppled dictator Nicolae Ceaușescu.

Meanwhile, on the economic front, an extremely gloomy report by the World Bank caused southern leaders further alarm. In the autumn before unification, one contemporary account described a situation in which the south's only export of any significance was honey:

The economy had effectively broken down; farmers refused to deliver food for the miserable prices they could get, for weeks the only food available in Aden market was potatoes, bread and onions. The government’s coffers were empty … South Yemen’s main export is honey, particularly prized in Saudi Arabia for its supposed aphrodisiac properties. 

Unification initially gave the new republic a coalition government in which the old southern regime was only a slightly-less-than-equal partner, but it wasn't long before Saleh's northern leadership gained the upper hand. Saleh was helped in this by the new democratic system – or rather, its demographics – since the southern population accounted for less than 20% of Yemen's total.

The two Alis: Al-Baid (left) and Saleh before they fell out

Despite unification of the northern and southern states there was no agreement on unifying their two armies. Southern leaders began to regret their decision to merge with the north and the result, in 1994, was a brief war of secession which Saleh's forces, aided by some Islamist elements, won decisively.

In the light of the current war, it's worth mentioning that the secessionists' chief backer in the 1994 war was Saudi Arabia – partly because it was fearful of a united Yemen on its doorstep and also because of Saleh's apparent support for Iraq and Saddam Hussein. The Saudis continued funding separatists for several years after the 1994 war but agreed to stop supporting them under the terms of the Yemeni-Saudi border treaty in 2000.

The latter years of Saleh's presidency saw a revival of separatist agitation, driven mainly by feelings of injustice at the way he had treated the south, especially in the aftermath of the 1994 war. There was no doubt that southern Yemenis had a raw deal under Saleh – though they were by no means alone in that.

But beyond airing grievances, the separatists have not made a persuasive case for independence and there is no reason to suppose independence would result in better governance: southern leaders, like those in the north, are a generally uninspiring bunch.
Bizarrely, rather than focusing on the future, separatist discourse often propagates an illusory view of the past in which the accepted historical narrative of the colonial period, and to some extent the socialist era too, has been turned on its head. Most Yemenis today are too young to remember what life was really like in colonial times, or even socialist times. At a conference in London, researcher Thanos Petouris explained:

"The colonial past of the south is no longer being seen as a period of oppression, social injustice and political marginalisation as the rhetoric of the nationalist organisations would have it but it has been transformed in collective memory into a period of almost golden age proportions, the restoration of which is to be desired.
"Essentially, the political and ideological language of al-Hirak, in so far as it can be seen as a unitary organisation, appears to have been locked between two extremes. The almost unreserved glorification of an imaginary colonial golden age on the one hand, and the political resurrection of former southern leaders on the other."

One former leader who keeps resurfacing is Ali Salim al-Baid. It was al-Baid who personally committed the south to unification with the north – at a one-to-one meeting with Saleh in a road tunnel in Aden (which later became known locally as the "Tunnel of Love"). It was al-Baid who later changed his mind and launched the 1994 war of secession but then disappeared to Oman, leaving others to carry on the fight.

Fragmentation by default

Internationally, there is no political support for dividing Yemen north and south or for breaking it up into smaller pieces. The UN is firmly committed to a one-state solution and the declared aim of the Saudi-led military coalition is to restore unity under the semi-legitimate rule of ousted president Abd Rabbu Mansour Hadi. 

Events on the ground, though, point in the opposite direction. While the Saudis continue bombing in the north, the Emiratis have been working more quietly, but with limited success, to establish a semblance of order in the south. From the coalition's point of view this is a necessary step and a prelude to extending "legitimate" government across the whole country. But the problem is that so far they have not been able to extend it by military means. The war appears to have reached an impasse and, after more than two years of fighting, the Houthis in the north show no sign of capitulating.

The result, unintentionally, is a de facto partition which in theory is only temporary but could easily become permanent. This, inevitably, has given encouragement to the southern secessionists. The other side of the coin, though, is that a separate state in the south also means a separate state in the north – one which under current conditions would be dominated by Houthis, thus terrifying the Saudis.

Worse still, there are now also divisions in the south, where Hadi's close ties with the Saudis have led to deteriorating relations with the Emiratis and his "legitimacy" is being increasingly challenged locally.

Under the federation plan, the south would be represented by two regions – Aden in the west and Hadhramaut in the east – and during the last week or so elements in both of these have claimed to be setting up their own governments.

As a result, Yemen now has four would-be governments with ambitions to rule nationally or regionally and halting the country's break-up looks more and more like an impossible task. 

Announcement of a "Southern Transitional Council"