The Big Read: Long-time allies torn apart

South Africa and Rwanda have had so much in common that, a few years ago, very few would have predicted that relations between the two countries would deteriorate to such an extent that they would both contemplate cutting diplomatic ties.

The tit-for-tat diplomatic row that resulted in the Kigali government expelling six South African diplomats in retaliation for the deportation of Rwandan High Commission officials from Pretoria marked the lowest point in a relationship that began with much promise in the early 1990s.

There are genuine fears that the situation could deteriorate even further, with diplomatic sources in Pretoria alleging that our government is even planning to expel the Rwandan high commissioner, effectively shutting down Rwanda's mission in South Africa.

How things have changed. Over the years, South Africa and Rwanda shared a very warm friendship that, some believed, dated back to the 1980s when some of the now-ruling Rwanda Patriotic Front leaders and the then exiled ANC's cadres were political refugees in Uganda.

Both parties came into power around the same time, 1994, with the ANC winning South Africa's first democratic election and the RPF taking over power by force following the Rwandan genocide.

In power, the ANC and RPF considered each other as sister parties, even embarking on similar nation-building projects after years of conflict.

When South Africa had the Truth and Reconciliation Commission in a bid to make sense of the human rights atrocities committed under apartheid, the Rwandans had their National Unity and Reconciliation Commission to bring the perpetrators of the genocide to book.

The two countries also worked in partnership to achieve political stability in the Great Lakes region, with the then deputy president, Jacob Zuma, working closely with the Rwandan government to bring about peace in Burundi.

But keen observers of regional politics would not have been entirely surprised by last week's developments.

Tensions between the two countries have been simmering for a number of years now. Some of the tension arose from what South Africa, and a number of other countries on the continent, see as Rwanda's destabilising role in the troubled eastern part of the Democratic Republic of Congo.

There were strong suspicions among African states, for instance, that Rwandan President Paul Kagame had a role in the M23 rebellion that threatened to plunge the DRC back into war.

But it is the killing and attempted assassination of a number of Rwandan opposition leaders and Kagame's enemies that have resulted in the tensions developing into a diplomatic crisis.

Four years ago, following the shooting of a Kagame opponent in Johannesburg, South Africa recalled its ambassador "for consultations" from Rwanda.

As far as diplomatic statements go, this was a strong message from Pretoria that Zuma's government was not happy with what it saw as Rwanda's illegal activities on South African soil.

Then, in December, came the killing of former Rwandan intelligence chief Patrick Karegeya at a hotel in Sandton, northern Johannesburg.

Although Kigali never admitted to involvement in the killing, statements by Kagame and other senior government officials suggested that they were delighted by Karegeya's death.

"We don't seek permission to defend our country," Kagame said in reaction to Karegeya's killing. "My job as president is to confront and defend Rwanda against people who want to destroy what we have been building."

His foot soldiers, it would seem, were again on a mission to "defend our country" when the Johannesburg home of former Rwanda army chief - and fierce Kagame critic - Faustin Kayumba Nyamwasa was attacked earlier this month.

Though Nyamwasa survived, the attack proved to be the final straw for South African security agencies, which say they have linked the hit directly to intelligence operatives based at the Rwandan High Commission.

Again, Rwanda did not deny involvement in the attack but reacted to the expulsion of its diplomats said to have had links to the attack by expelling South Africa's diplomatic staff from Kigali.

"We have expelled six South African diplomats in reciprocity and concern at South Africa's harbouring of dissidents responsible for terrorist attacks in Rwanda," Kigali said.

Kagame's government and various commentators in Rwanda often express frustration at what they see as South Africa's refusal to extradite politicians and former security chiefs they accuse of being involved in planning "terror" attacks against the Rwandan state.

According to them, numerous requests have been made to Pretoria over the years to hand over Nyamwasa and Kareyega. Instead of heeding the request, Pretoria put the two on its witness protection programme.

Kigali blames Pretoria's reluctance on the personal relationships that have existed between the likes of Nyamwasa and Kareyega and some senior South African government officials.

Sadly, our government has not seen fit to publicly explain its position - hence, in the eyes of Rwanda's sympathisers, lending credence to Kigali's claims that the Union Buildings was sacrificing state relations in favour of protecting personal friends.

But, whatever our government's reason might be, the assassination of, and attacks on, Rwandan dissidents can never be tolerated.

Pretoria was right to expel the Rwandan diplomats if indeed it had evidence of their involvement in the killings.

South Africa cannot protest against the interference of foreign powers in the affairs of other countries and then turn a blind eye to the criminal activities of a foreign government on our own soil.

If Kigali has evidence that some of the Rwandan refugees who have made South Africa their home were involved in criminal activities, let it approach our authorities and courts with that evidence.

There is no justification for political assassinations.