Rwanda’s unilateral decision to close its busiest border crossing with Uganda at the end of February has disrupted trade and laid bare simmering tensions between the two East African nations. The neighbors have had intermittent disagreements in the past but mainly were allies in recent years, and helped quell armed conflict during and after a civil war in the Democratic Republic of Congo. An escalation of Rwanda-Uganda animosity could derail two of Africa’s fastest-growing economies and destabilize the greater region.

1. Why did Rwanda shut the border crossing?

President Paul Kagame’s government says it needed to carry out repairs on the road serving the Katuna border post, which handles most trade between the two countries. The closing caught Uganda unaware and stranded dozens of trucks that were en route from its cities to Rwanda’s capital, Kigali, and beyond to Burundi, Congo and Zambia. Uganda’s government has yet to establish whether “there is another reason beyond the road construction work” for Rwanda’s action, spokesman Ofwono Opondo, said on March 6.

2. What other reasons could there be?

Both governments allege that the other is seeking to undermine and destabilize their national security, according to Frederick Golooba-Mutebi, an independent political analyst who focuses on Africa’s Great Lakes region. Rwandan Foreign Minister Richard Sezibera has accused Uganda of supporting the Democratic Forces for the Liberation of Rwanda, a group of rebels that includes perpetrators of the the 1994 Rwandan genocide. His Ugandan counterpart, Sam Kutesa, denies the allegation. Sezibera also alleges that Uganda has arrested and tortured 190 Rwandan citizens over the past few years and deported 986 of them. Uganda says it detained some Rwandans who were suspected of abduction.

3. Why is this all flaring now?

There have been recent signs that all is not well between Kagame and Ugandan President Yoweri Museveni, who fought together to bring an end to military dictatorship in Uganda in the 1980s and to halt the Rwandan genocide. When Museveni replaced his police chief last May, some analysts suggested he was trying to stop Rwandan spies from infiltrating the Ugandan security forces to eliminate rebels feared to be recruiting members from refugee camps in Uganda. (Rwanda had previously asked Museveni’s administration to help deal with the rebels, to no avail, according to Kigali-based government officials.) Also there may be lingering distrust between the two nations over the so-called six-day war they fought in Congo almost two decades ago. While they were ostensibly allies, their troops ended up clashing.

4. Where might this go from here?

Kutesa says Uganda is ready to strengthen ties with Rwanda, which he describes as “a brotherly country.” But Rwanda says repairs on the road serving the closed border post could continue until May, and it’s diverted heavy trucks to another crossing. It’s also advised Rwandan citizens not to enter Uganda, warning they could be arrested. Museveni and Kagame have held talks in the past to ease previous tensions. A meeting between them could help end the latest impasse, but nothing has been scheduled as yet.

5. What’s the worst-case scenario?

An all-out war is considered highly unlikely. But if tensions don’t ease soon, there’s a risk they could undermine stability in the region, since Museveni and Kagame are both seen as key to keeping peace beyond their borders. The standoff could also set back regional integration efforts that are taking place under the auspices of the East African Community and could ultimately lead to the formation of a monetary union and political federation.

6. What are the economic interests at play?

Uganda, with discoveries of as much as 1.4 billion barrels of recoverable oil, is looking to start crude production by 2022 and wouldn’t want a dispute with its neighbor to disrupt those plans, which have been decades in the making. Total SA, Cnooc Ltd. and London-based Tullow Oil Plc are developing the oil fields, while a General Electric-led consortium was chosen to set up Uganda’s first oil refinery to process their output. Uganda is also Africa’s biggest exporter of coffee and plans to quadruple production by 2025. Rwanda is ranked by the World Bank as mainland Africa’s easiest place to do business, and Kagame similarly wouldn’t want the border standoff to undermine his efforts to position his landlocked country as an investors’ haven.

The Reference Shelf

• A Bloomberg story about the border post closure and another about the counter-accusations the two nations have made.
• The IMF’s summary page on Rwanda.
• A QuickTake about economic integration efforts in Africa.