The United States is knee-deep in the Horn of Africa and could easily get deeper.
The Horn consists roughly of Eritrea, Djibouti, Ethiopia and Somalia and it is separated from the Middle East by a relatively narrow strip of water. Assorted fires are burning in the region. Most of them are local, although each is capable of flaring into a serious conflagration, given the world's stake in the area.
Ethiopia and its former component, Eritrea, have a border dispute that led to bloody conflict. It was resolved in principle, but the agreement has not been implemented.
Eritrea, becoming the region's spoiler, has grabbed a piece of Djibouti, probably to use as a political pawn, but it nonetheless represents an alarming development for the tiny nation. The United States has 2,500 troops stationed in Djibouti as part of its new Africa command.
Djibouti is a sliver of stability in an increasingly bad neighborhood. It is vital to regional giant Ethiopia, which is landlocked. Djibouti's railroad and port provide Ethiopia access to the sea for imports and exports. If Eritrea were to seek to close either, Ethiopia would intervene militarily. The United States supported Ethiopia with air strikes when it invaded Somalia a couple of years ago.
Somalia, to the degree that it remains a viable country, is up for grabs by various domestic elements. It has, in principle, a government, unelected but supported by the African Union, the United Nations and the United States, but it is close to needing last rites as an Islamist militia lays siege in Somalia's ruined capital, Mogadishu.
Probably only international forces can save that government, but if that were to occur its future would be further damaged in the eyes of the Somalis by its dependence on foreigners. The absence of a credible authority is what makes piracy off its shores possible. Efforts to suppress it are costing a lot, including to the United States.
Finally, to a small degree, the Horn is a venue for economic and commercial competition among the Europeans, Iran, the Gulf Arabs and the United States. It is in the interest of all of them that the relative brushfires of conflict in the Horn not expand. Peace there can also serve as a starting point for constructive dialogue, particularly between America and Iran.