Kigali - The deployment of a UN force of African troops in eastern Democratic Republic of Congo threatens to draw Rwanda into a damaging conflict with African powers and derail its economic "miracle" if donors again cut aid over Kigali's involvement there.
President Paul Kagame has twice marched his troops over the border since Rwanda's 1994 genocide. One of the justifications he cited was his country's national security, the need to counter a threat Kigali said was posed by those behind the genocide who had found haven in eastern Congo.
Rwanda, though, has usually managed to fend off criticism from Western allies who accuse Kigali of backing the M23 rebel group they say has stoked the conflict in a region rich in minerals with a population mired in poverty.
Rwanda's fortunes took a tumble last year, when donors' patience snapped and they cut back on aid that accounts for about 40% of the budget after UN experts detailed Rwandan support for the M23 - charges Kigali vigorously denies.
Now Kigali faces a new test after a flare-up last month drew in a new UN intervention brigade of South African, Tanzanian and Malawian peacekeepers with a robust mandate to "neutralise and disarm" armed groups.
This, combined with renewed diplomatic pressure for a negotiated peace coming from UN, US and European envoys and regional leaders meeting in Uganda this week, may give Kagame pause as he ponders his next move over his western neighbour.
"The arrival of Tanzania and South Africa on the scene... with boots on the ground is a new aspect," Jason Stearns, a project director at regional think-tank the Rift Valley Institute, told Reuters.
"The political role that contributors to that intervention brigade play is at least as important as the military role," said Stearns. "Often peer pressure matters more than donor dollars," he added.
Rwanda threatened to send troops back over the border to protect its security after it accused Congo's army of firing shells into its territory in the confused skirmishes north of the Congolese frontier town of Goma at the end of August.
"If a diplomatic resolution means Rwanda standing by, arms crossed, waiting for its territory to be bombed and its people killed, then diplomacy is definitely off the table," Rwandan Foreign Minister Louise Mushikiwabo told Reuters on 30 August.
Pretext to invade
But UN peacekeepers said the shells that fell in Rwanda were fired from M23 positions and Congo alleged the rebels' firing was to give Rwanda a pretext to invade.
A misstep in Rwanda's diplomatic and military balancing act risks derailing its economic "miracle" if increasingly anxious donors turn off the taps again. It could also push Kigali into a damaging tussle for influence with powerful African rivals like South Africa and Tanzania whose troops are on the frontline.
"Rwanda is analysing how far they can go without losing everything," said one diplomat in the Great Lakes region. "They have a lot of allies but it's getting harder for them, especially now the Americans are putting the pressure on."
The United States, a big aid contributor, weighed in on 25 August telling "Rwanda to cease any and all support to the M23."
Rwanda insists its national security is at stake. Eastern Congo, it argues, still harbours the Hutu extremists behind the 1994 genocide that killed 800 000 Tutsis and moderate Hutus. Kigali has long accused Congo's armed forces of tolerating, and even cooperating with, these Hutu FDLR insurgents.
It is a view that wins broad support in Rwanda, a land-locked nation a fraction the size of Congo that has ambitions to be a tech-savvy logistics hub mirroring Singapore in Asia.
Hungry for that vision, many Rwandans fear the cost of more military adventurism in Congo that has already involved two wars, the last ending with a peace deal in 2002. When donors cut back aid last year over the alleged support for M23, belt tightening cut percentage points off Rwanda's growth.
For now, donors have not threatened a repeat that could hurt what they see as a model for Africa. But there are rumblings.
"There is a strong perception [Rwanda is supporting M23], there seems to be some evidence for that," said UN special envoy to the Greak Lakes Mary Robinson before the regional summit this week in Uganda. "This is having an impact on how donor countries perceive the situation."
Often speaking in hushed tones because of Kagame's authoritarian style of rule, Rwandans worry a new intervention by their army in the western neighbour could threaten the achievements of their still genocide-scarred nation that now boasts smart roads, better schools and flourishing businesses.
"We are worried about what will happen if Rwanda decides to attack Congo," said 28-year-old Kigali shopkeeper Jean Claude, giving only his first name. "More aid money could be suspended and Rwanda's reputation will get worse."
Parliamentary elections later this month may give the government food for thought. While there is no significant opposition to challenge Kagame's ruling Rwandan Patriotic Front, the vote will test the public mood and the government's mandate.
Such factors could play into a struggle for influence within Rwanda's elite between hardline security-minded politicians, wary of relinquishing vested interests and influence in mineral-rich east Congo, and those counselling more moderation to avoid hurting Rwanda's economic ambitions, analysts and diplomats say.
"The strategy should be to push the Rwandan government towards the more moderate members of its elite, those that privilege economic liberalism and opening to the world over security," said the Rift Valley Institute's Stearns.
But some see signs of greater caution this time in Kigali over the most recent fighting in eastern Congo.
For all the talk and witness accounts of a Rwandan military build-up on the Congo border, clashes between M23 and Congolese forces backed by the UN African peacekeepers of the new brigade subsided at the start of this month. M23 forces gave up strategic ground north of Goma.
Although Rwanda strenuously denies any links to the group, analysts and diplomats say the influence of the M23 as a proxy force, at least for now, seems to have been eroded.
New military foray
They add it could struggle to regroup and rearm without a level of Rwandan support that would have to be far more overt and carry the risk of international condemnation.
Rwanda must calculate the cost of pitching itself into a new military foray in Congo when South Africa and Tanzania have put their interests and troops in the conflict zone.
South African President Jacob Zuma this week expressed strong support for the new UN brigade, including more than 1 000 of his country's troops, which last month went into action for the first time against the M23 rebels.
"The job of the UN is to defend the people," Zuma told Reuters at a media briefing in Pretoria. He added this did not mean abandoning efforts for a negotiated end to east Congo's conflict. More than five million people have died there through violence, hunger and disease since 1998.
Residents on both sides of the porous and violence-racked border look for peace.
"We are familiar with unrest here and we will just wait and see what happens," said Rwandan teacher David Nshimimana, 42, close to Congo's border. "But of course we are afraid."