In May 2009, Chad and Sudan signed a ceasefire agreement in Qatar.
It was supposed to bring an end to - or at least a break in - the fighting between the two nations.
But within hours of the deal, Chad was accusing Sudan of backing anti-government rebels and within days carried out a series of cross border air raids into Sudan.
The latest violence is not a new development. The two nations have been uncomfortable neighbours for decades, but tensions have escalated in the last four years.
Since the end of 2005, Chad has been in a state of civil war with rebel groups trying to oust Idriss Deby, the country's president.
Chad has repeatedly claimed that the Sudanese government supports and helps to arm these groups.
Just what is at the root of it all? And could this be a new flashpoint on the volatile African continent?
Inside Story, with presenter Kamahl Santamaria, discusses with Fouad Hikmat, the project director for the Horn of Africa at the International Crisis Group in Nairobi, Roland Marchal, a senior fellow at the National Centre for Scientific Research in Paris, and Abdel Wahab Al Effendi, a senior research fellow at the Centre for the Study of Democracy at the University of Westminster.
This episode of Inside Story aired on Sunday, May 24, 2009.
Source: Al Jazeera