Tensions have lessened along the border between Ethiopia and Eritrea after Addis Ababa complied with a United Nations’ demand to withdraw troops from the unmarked frontier, a senior U.N. official said on Wednesday. The United States said on Monday it would send a special mission to the Horn of Africa neighbors in a diplomatic push to mark the frontier and avert a possible repeat of their 1998-2000 border war that killed 70,000 people. Full Story