In January this year Sudanese troops were sent to man the country’s border with Eritrea.
The border was sealed: trade between the neighbouring states ceased.
This has caused real hardship for many on both sides of the border - but particularly in Eritrea, which relies on imports from Sudan.
So what is behind these dramatic events?
The origins of the dispute can be traced back to a visit to Eritrea by the Sudanese First Vice - President and National Prime Minister, Lt. Gen. Bakri Hassan Salih in December last year.
The official Sudanese statement said the two sides had "discussed progress of the bilateral relations between two countries and issues of mutual concern.”
But Sudanese sources suggest the discussions were far more dramatic. Sudan has been drifting away from its traditional alliance with Egypt, and closer to Ethiopia.
Khartoum has sided with Addis Ababa rather than Cairo over Ethiopia’s Grand Renaissance dam on the Nile.
At the same time relations between Eritrea and Egypt have been warming. During General Salih’s visit to Asmara, President Isaias Afwerki suggested that the time was ripe for the General to replace President Omar al Bashir as Sudanese head of state.
Apparently speaking with the authority of Cairo, President Isaias said that such a move would be supported by both Eritrea and Egypt.
When General Salih returned to Khartoum the news was received with consternation.
Sudanese troops were rushed to the Eritrean border and the border sealed.
