Evaluate the international community's response to the 1994 rwandan genocide. what steps could have been taken to limit the event?

In April 1994 in Rwanda (East Africa) began the genocide of Tutsi - an ethnic minority, which for centuries dominated the Rwandan majority - Hutu. During the 100 days of incredible violence, about 800 000 Tutsi and moderate Hutu were murdered.  The international community, unfortunately, didn't respond to this event on time. The conflict was considered as an internal case and the Security Council of the UN didn't decide to intervene. Even though the scale and character of the conflict was well known the United States didn't want to get involved because of a painful experience from its intervention in Somalia in 1993 (the story was presented in the movie Black Hawk Down). 
The UN troops arrived in Rwanda when the major fights were over. They assisted only by the burial of deaths and protected the survivors. Today we know that other countries (for example France and China) were selling arms to the Rwandan government. 
What could be the response? The international community could prevent the growing hostility and animosity between Hutu and Tutsi already before the genocide. They should have introduced an embargo on arms in order to prevent the escalation of violence. When the conflict had begun, a military intervention should have taken place. 

Magma is outside the volcano  and lava is inside the volcano.