WHEN a Hutu politician says it is time to “pulverise and exterminate” rebels who are “good only for dying”, outsiders should sit up. When he talks of spraying “cockroaches” or urges people to “start work”, it is hard to miss the old codewords for massacring Tutsis. When the politician is not some obscure backbencher but the president of the Burundian Senate, the world should be alarmed. History does not always repeat itself in central Africa, but it rhymes cacophonously. Rwanda and Burundi, two small countries with Hutu majorities and Tutsi minorities, have seen large-scale ethnic massacres in 1959, 1963, 1972, 1988, 1993 and 1994. These were not, as some outsiders imagine, spontaneous outbursts of tribal hatred. They happened because those in power deliberately inflamed ethnic divisions. The Rwandan genocide of 1994, in which perhaps half a million Tutsis were hacked to death, was meticulously planned by Hutu army officers and politicians. They did it to avoid sharing power with Tutsi rebels after a peace accord to end a civil war. They raised a militia, cranked up the genocidal propaganda and imported hundreds of thousands of machetes in advance. The outside world barely noticed until it was too late. The genocide ended only when a Tutsi army swept in to stop it, led by Rwanda’s current president, Paul Kagame.

Today in Burundi, many people hear echoes of 1994. Since last April, when President Pierre Nkurunziza, a Hutu, declared that he would seek a (probably unconstitutional) third term in office, the country has been plunged into turmoil. Bujumbura, the pretty capital on the shores of Lake Tanganyika, has endured a botched coup and street fighting. Its cobbled streets are deserted after dark and ring to the sound of gunfire. In recent months repression has gathered steam. Mr Nkurunziza’s youth militia terrorises his opponents, many of whom are Tutsis. Hundreds, perhaps thousands, of people, mostly young men, have been “disappeared”. Torture is rife. Maybe 250,000 people have fled to neighbouring countries; more are displaced internally. The economy is collapsing.

Tutsis have cause to be afraid. They are quietly being purged from the army. On the radio, they hear murderous rhetoric of the sort that preceded the Rwandan genocide. As was the case in Rwanda in 1994, today’s Burundian government feels besieged. Several of its members have been assassinated, and rebels have launched attacks into Burundi from foreign refugee camps. It is far from clear that genocide is looming. But even if the worst is unlikely, it makes sense to take precautions. History shows that calamity can happen very quickly: Rwanda’s genocide lasted a mere 100 days. And conflict can often spread across borders: the ripples from Rwanda started a great war in Congo that eventually claimed even more lives.

A short fuse

What can be done to defuse Burundi? The European Union is cutting aid to its government, but Mr Nkurunziza has simply redirected spending from health and education to the security forces, leaving the UN and charities to look after children and the sick (see article). The African Union considered sending 5,000 soldiers—but then backtracked when Burundi objected. The UN has suggested sending peacekeepers but has done nothing. This is not good enough.

More targeted sanctions, which hurt the president’s cronies personally, are needed. If things get worse, outsiders should be ready to send in troops, under the aegis of the African Union or the UN. There are 19,000 UN blue helmets just across the border in Congo. They should be prepared to step in, and the great powers should make sure that Mr Nkurunziza knows it.