Mitt Romney will have surprised many by bringing up the situation in Mali in Tuesday night’s Presidential debate. Countries in the Sahel rarely trouble US public opinion, or public opinion in many other parts of the planet.

Mali is a very poor country indeed. Mean hourly wages were 65 US cents in 2009, but formal work is relatively rare, with around two-thirds of Malians surviving from subsistence agriculture. Only 12 nations rank lower on the UN’s Human Development Index. One Malian child in nine dies before his or her first birthday. The country’s main exports are cotton and rice, both of which are in direct competition with heavily subsidised US producers. Roughly 90% of Mali’s 15 million people belong to various Black African ethnic groups and are concentrated in the relatively fertile and densely populated south, especially along the Niger River. 10% are Tuareg or Moorish and are mainly spread across the vast desert expanses of the north.

Roughly 90% of the population is Muslim, with the remainder even split between Christians and traditional believers. I know we’re always told that interfaith relations are good in every Muslim majority country, even when that transparently isn’t the case, but Mali, and indeed the Sahel more generally, seems to have long had peaceable and tolerant co-existence between faiths.

Despite its poverty, Mali had until this year been a rare case for optimism in West Africa. After the usual phase of single-party nationalist rule with an allegedly socialist tinge, Mali transitioned to multi-party democracy in the early 1990s and pretty much stayed there. The country remained desperately poor, but was growing just about enough to cover its rapidly expanding population. Elections were peaceful and sometimes even competitive, if marked by lamentably low participation. The country struggled with hunger, but avoided conflict both internally and with its neighbours. Even the national football team put together a series of semi final performances at the Africa Cup of Nations.

This year has been the most tumultuous in Mali’s half a century of existence. In January, a rebellion broke out in the north, fuelled by a tidal wave of cheap weapons flooding across the Sahara after the end of the Libyan Civil War. As well as the usual tidal wave of small arms, mercenaries fleeing post-Gaddafi Libya brought heavy machine guns and rockets, and even light artillery are rumoured to have slipped across Libya’s borders. The Tuareg in both Mali and neighbouring Niger had long complained of central government neglect and the granting of mining concessions to foreign companies who they felt damaged grazing areas while giving little back to locals. Rebel demands were confused – while there was a nominal commitment to independence for the North, this may have been as much a bargaining chip as a concrete demand. But the rebellion gathered strength week by week, and by March, the rebels were solidly in control of the far north and moving steadily south. The US began supplying government troops, but that was at best slowing the advance of well-motivated rebels against badly-led and poorly-armed state forces.

Then in late March, just before elections were took place, the army revolted against the government’s handling of the crisis, and forced the President from power. Civilian rule, if not democracy, returned a few weeks later with the previous speaker of parliament elevated to the Presidency as a compromise candidate, with a mandate to renew the offensive against the rebels.

While one wing of the rebel forces, led by the ethnic Tuareg MNLA (official website makes fascinating reading), is primarily concerned about traditional northern grievances against Bamako, the other wing, Ansar Dine or the ‘Defenders of the Faith’ instead seeks the imposition of Sharia Law across the country. Ansar Dine has links with Al Qa’eda.

In early April, just as the new President was taking power in Bamako, the relationship between the two wings of the rebellion was breaking down in the north. Sharia law was imposed in Timbuktu, with practically the entire Christian population of the city fleeing within days after a prominent Christian leader was beheaded. Further west, in Gao, Ansar Dine banned bars, video games, Western music and even football as Unislamic. Churches and even Sufi shrines, thoroughly Muslim but regarded as heretical by strict Salafists, have been destroyed. Tuareg Islam has always tended towards the mystical rather than the doctrinaire, and the attempt to impose Sharia proved a step too far for many northerners. Since the summer, the MNLA and Ansar Dine have repeatedly clashed, using some of the military hardware that had slipped down from Libya. Moors and members of black ethnic groups in the north have begun forming their own, well armed, ethnic militias.

In the south, racial tension has emerged for the first time in living memory with an estimated 60,000 Tuaregs and Arabs fleeing Bamako after a series of reprisal attacks, sometimes by isolated individuals, sometimes by mobs.

While American support for the government so far seems to have been limited to logistics and ‘military advice’, the French, who have never really got used to the idea that their former African countries are actually independent, are sending surveillance drones to Mali right now. Doubtless French special forces are also preparing to do the things that French special forces do in Francophone Africa. AP also reports that top-level French and American diplomats are holding talks in Paris to discuss next moves in Mali. And so the West inches its way into another land war in the Islamic world, with all the potential for escalation that implies.

As well as Mali, neighbouring Niger is also being destabilised by the tide of weapons and former mercenaries from Libya. Neither Niger nor Nigeria has the capacity to patrol their 1,500 km border effectively. I’ve yet to see any concrete evidence that weapons from Libya are a part of what’s fuelling the renewed upsurge in Boko Haram violence in Northern Nigeria, with close to 1,000 killed by the Islamist group so far this year. But looted Libyan weapons have also, inevitably, been found in Nigeria. Five days on a truck and a couple of border crossings are all that stand between an American supplied heavy machine gun in Libya’s Wadi al Shati and an attack on a church in Maiduguri or Bauchi. Even without any ideological motivation, there are plenty of people in Libya who have weapons and need money.

One very much doubts that any Western policy maker envisaged the destabilising effect of supplying weapons to Libya’s rebels on countries to the south. The law of unintended consequences kicks in just as viciously, perhaps even more so, when arms are supplied in quantities to irregular forces as it does when troops are actually put on the ground.

The US Presidential foreign policy ‘debate’ on Monday night took place between two men who seem to think the law of unintended consequences doesn’t apply to the United States. America has already started supplying weapons to the Syrian opposition. Mitt Romney wants to escalate that support, palling up with Saudi Arabia and Qatar to send tanks and helicopters to a place where some, perhaps most, will be in control of Al Qa’eda linked groups. A nation that essentially created Al Qa’eda by arming the Taliban against the Soviets in 1980s Afghanistan seems to have learned few lessons. Perhaps the deteriorating situation in Mali might give them pause for thought before American weapons flow into Syria, then across its borders, with consequences no-one can foresee from here.