Why is America against the government of Eritrea?

It's not entirely accurate to say the United States is against the government of Eritrea. The United States has a policy of helping newly independent countries and establishing alliances with them. However, the country of Eritrea has been involved in a long and brutal conflict with Ethiopia, and as a result, it has not had a very stable leadership nor has the country's economy been stable-- some reports say more people are in the military than in the workforce. Over the past few years, the government was accused of aiding Islamist forces in Somalia, which contributed to destabilizing the region. This is why some western countries, including the US, have not been entirely supportive.