The Ethiopian Government must respond quickly with Tanks fit for the flat Gambellan terrain to overpower the terrorists. Gambella must be placed under state of emergency and ENDF must close the borders.
Ethiopia should also create a buffer zone and invade South Sudan and occupy areas with Oil resources that are near Gambella. This is the perfect Casus Belli for the Ethiopian Government to seize South Sudanese Lands with Oil and begin extracting
