Belgian stirring of the conflict pot goes back to the 50s according to what I've read, when they switched from using the Tutsis as their channels of power to the Hutus, because the better educated Tutsis were getting too uppity and demanding independence. Mitterand is also to blame, indirectly, for the 1994 massacre by sending paras to repel the 1990 invasion in the name of Francophonie. A conflict going back to Fashoda. Apparently.
The IMF is more to blame.
It began before the IMF existed. Dammit, why this knee-jerk rejection of analysis? Allocate blame to the usual suspects, then look for evidence.
No kneejerk. This is the result of a great deal of research. Yes, there were conflicts there, and a divide. But the difference between Rwanda & Burundi, which meant one descended into brutal civil war, and, despite violence, the other did not, was very much the use of Structural Adjustment Programmes as an act of war.
Burundi didn't descend into brutal civil war? In which universe? A few hundred thousand dead (again) is just 'violence'.
Of course, the attempt to exterminate the Tutsi population of Rwanda had nothing to do with a small Hutu clique exploiting tensions to try to destroy the internal power base of the mostly expatriate Tutsi army which invaded from Uganda, but was everything to do with an IMF 'act of war'. And the structural adjustment explains why Rwanda descended further into horror even than Burundi. Never heard of the IMF structural adjustment programmes in Burundi, have you, or you'd know that both Rwanda & Burundi had more or less simultaneous programmes in the early 1990s?
Now do you see what I mean? In the selected sources you rely on, the fact that Rwanda had a structural adjustment programme just before the genocide is obviously the cause of the genocide. Since Burundi didn't have an equally* ghastly episode, then clearly it didn't have a structural adjustment programme.
Rwandan politics, such as the existence of a large & organised (with the co-operation of a neighbouring state) expatriate population dating back to inter-ethnic conflict over 30 years earlier, don't count. Nor do the ambitions of the leaders of neighbouring states. The poor natives are helpless puppets dancing on the strings pulled by white people, & incapable of having their own motivations, or acting on their own initiative.
*Unutterably horrible, but much less intense.