This sounds incredibly ill-advised to me: “American officials acknowledged that they tacitly supported Ethiopia’s approach because they felt it was the best way to check the growing power of the Islamists, whom American officials have accused of sheltering terrorists tied with Al Qaeda.”
There’s just no way that a foreign invasion by a Christian army of a Muslim country is going to check the growing power of the Islamists in any meaningful sense. The exact quantity of acreage under Islamists control is no skin off our backs. We need to worry about people plotting against the USA being sheltered somewhere in that acreage. Encouraging Ethiopia to go to war with the Islamists merely encourages them to collaborate in efforts to attack the United States. If the Ethiopian military could somehow eliminate Somali Islamism as a social and political force, that would be one thing, but there’s just no way they can do that.