Observers warn that a civil war in Ethiopia could spill over into neighbor nations such as Sudan, Eritrea and Somalia NAIROBI, Kenya (AP) ? Ethiopia moved Saturday to replace the leadership in the country?s defiant northern Tigray region, where clashes between regional forces and those of the federal government have led to fears that the major African power could slide into civil war. Tigray?s leader told the African Union that the federal government was planning a ?full-fledged military offensive.? Neither side appeared ready for the dialogue that experts say is needed to avert disaster. The upper house of parliament, the House of Federation, voted to set up an interim administration,...