"This area is a vital artery of world trade that includes the main shipping routes from the Far East to Europe and the US with over 23,000 shipping movements per year. Over one third of the world's oil passes through the Area of Operation (AOR) each year. In addition the AOR contains three narrow waterways, know as "choke points', where vessels are required to pass closely between two shorelines""
Combined Task Force 151 is deployed to the Gulf of Aden and off the coast of Somalia, covering 1.1 million square miles. It has been commanded by the U.S., Denmark, Turkey, Pakistan and South Korea. CTF 151 coordinates all its activities with NATO and the European Union Naval Force Somalia, which are conducting Operation Ocean Shield and Operation Atalanta, respectively.
Combined Task Force 152 operates in what Combined Maritime Forces refers to as the Arabian Gulf; that is, what most of the world knows as the Persian Gulf. The use of the first description is a naked affront to Iran and is meant to be just that. CTF 152 operates in conjunction with the navies of the six Gulf Cooperation Council member states: Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates. It has been commanded by the U.S., Britain, Italy, Australia, Bahrain, Kuwait and the United Arab Emirates.
The Combined Maritime Forces website offers this concise background information (and at least implicitly reveals why the CTF 152 is present where it is):
"Today the Gulf is one of the most strategic waterways in the world due to its importance in world oil transportation. It contains in the region of 700 billion barrels of proven oil reserves, representing over half of the world's oil reserves, and over 2,000 trillion cubic feet of natural gas reserves (45% of the world total). Arabian Gulf countries maintain about one-third of the world's productive oil capacity. The majority of the oil exported from the Arabian Gulf is transported by sea."
The U.S. and its military allies in Canada, Europe, the Asia-Pacific region and the Persian Gulf have their warships and shipborne aircraft positioned in the most economically and geostrategically vital stretch of water in the world. To protect their own interests in the manner the world's sole military superpower employs throughout most of the planet -- maintaining the presence of overwhelming firepower -- and whenever it suits them to threaten the fundamental interests of others.