“The general offensive has begun,” said Seydou Ouattara, the military spokesman of the man who claims to be Ivory Coast’s legitimate president, Alassane Ouattara, on Monday (March 28). “We’ve realised that this is the only way to remove [the incumbent president, Laurent Gbagbo].” On the same day Ouattara’s troops seized two cities in the west of the country, Daloa and Giglio.

While ragtag little armies surge back and forth along the North African coast like a high-speed replay in miniature of the Western Desert campaign in the Second World War, a much bigger war is getting underway 1,500 kilometres to the south. And although there are 9,000 United Nations troops on the ground in Ivory Coast, quite unlike the air-strikes-only intervention in Libya, the UN troops in Ivory Coast will not intervene to stop the war there.

The UN soldiers, all from African countries, were sent there to police a truce between the Muslim north of the country, which has been in the hands of the rebel New Forces since 2002, and the government of President Laurent Gbagbo, which controlled the largely Christian south. They were also there to supervise the election last November that was supposed to end the division of the country.

Unfortunately, the election didn’t work. Ouattara claimed victory and 3,000 international election observers backed him up, but an ally of Gbagbo’s on the Constitutional Court declared half a million of Ouattara’s votes invalid and said Gbagbo had won. Back to Square One.

Ouattara declared himself president, appointed the commander of the New Forces, Guillaume Soro, as his prime minister, and holed up in a hotel in Abidjan, the commercial capital, with three UN tanks parked out front to deter an attack by Gbagbo’s forces. Gbagbo insisted that he was still president, and threatened to use the army against Ouattara.

The UN troops will not intervene decisively because they were not sent to Ivory Coast to take sides in a large civil war, which is how this could end up. It isn’t just a quarrel between two stubborn men. It is about a probably irreversible transfer of power from the Christian south to the Muslim north in West Africa’s richest country, and there are those in the south who will fight to prevent that.

Christians used to be the majority in Ivory Coast, and they would probably still be if not for the estimated four million illegal immigrants who have poured into the country in the past two decades. Almost all of them came from the countries to the north, Burkina Faso, Guinea and Mali, which are entirely Muslim. Around a million of them are in Abidjan, but most stayed in northern Ivory Coast—Ouattara’s territory.

Gbagbo’s real complaint about the recent election is not that the vote was rigged but that the voter registration was rigged: that hundreds of thousands of illegal immigrants were registered as voters by sympathetic Muslim officials across the north. It may not be true, but it certainly could be. And Muslims certainly did vote overwhelmingly for Ouattara.

There was no hostility in the relationship between Muslims and Christians in Ivory Coast 50 years ago: this is entirely a product of politics. Just as every evolutionary niche is always filled, so is every political niche, including the one inhabited by politicians whose method is to build support in one ethnic or religious community by stirring up fear or jealousy of another.

Ouattara and Gbagbo both belong to that political species, although they would deny it with their last breath. They have succeeded so well that Ivory Coast now stands on the brink of a Muslim-Christian civil war (although the news agency reports hardly ever mention this key feature of today’s Ivorian politics). The normal result would be a hardening of the current partition of the country, but first there will be one last roll of the dice.

Gbagbo is in deep trouble. The West African central bank has denied him access to Ivory Coast’s accounts, the country’s main cash crop, cocoa, is being boycotted by the international community, and last month he had trouble paying salaries and pensions to civil servants—including the military. Some got part of what was due them, some none at all.

Gbagbo must pay them again this week, and he probably doesn’t have the money. His army has lost every clash with Ouattara’s New Forces since the November election, and he has lost control of the mainly Muslim quarters of Abidjan to the “Invisible Commandos”, essentially an urban branch of New Forces.

So Ouattara is going for broke. Last week he rejected the peace envoy appointed by the African Union, and at the weekend the New Forces launched their final offensive. Or at least they hope it will be the final offensive.

So far they are doing well, and they may just roll over Gbagbo’s disintegrating army and reunite Ivory Coast by force. Even that would leave great bitterness in the south—but it is also possible that Ouattara’s big push will stall after a few days. African armies tend to be weak in logistics, and they usually run out of supplies when they advance too fast. Then it turns into a long, mostly static civil war.

Either way, the old Ivory Coast is finished. What replaces it may be very ugly.