Dispatch from aboard the USS Harry S Truman

The nuclear-powered American aircraft carrier covers an area stretching from Kuwait to the Red Sea, 'ensuring the maritime security of the region'.

NORTHERN ARABIAN SEA // Its crew of 4,600 and the squadrons of jet fighters that it launches into the skies across the region help to underpin a naval power that spans the globe. But for Joe Clarkson, captain of the USS Harry S Truman, a Nimitz-class nuclear-powered aircraft carrier patrolling the northern Arabian Sea, the vessel's mission extends beyond that of simply supporting America's military campaigns in Iraq and Afghanistan.

He believes its sophisticated weaponry also provides a crucial bastion of security that shields the Gulf's inhabitants and their trading routes from aggressors. "Supporting the coalition troops in Afghanistan and ensuring the maritime security of the region - as 90 per cent of the global trade is carried out via sea routes - is the focus of our deployment under the 5th Fleet command," said Capt Clarkson, referring to the US naval force, based in Manama, Bahrain's capital. The fleet patrols a huge area, extending from Kuwait, through the Gulf into the Arabian Sea and into the Red Sea.

Every day, scores of tankers transport millions of barrels of oil across the area's often-troubled waters, including through the Straits of Hormuz and sometimes perilously close to Somalia's pirate-infested coast. To secure the safe passage of this never-ending stream of merchant vessels, the USS Harry Truman employs its formidable air power. On its flight deck there is a steady roar of heavily armed Boeing Super Hornets as they are catapulted into action. In the early morning hours, their engines emit a luminous glow of oranges and yellows as they thunder off the deck. Landing aircraft are pulled to a halt by a sophisticated system of arrester wires.

Seaman Braydon Duby, one of the crew that helps land and recover the aircraft, said: "I am on the best ship with the best crew. That gives me confidence that we are going to get the job done on this deployment." Besides its sea patrols, the USS Harry Truman's air wing of 60 aircraft flies almost daily sorties providing bombing and reconnaissance missions for the International Security Assistance Force in Afghanistan.

"Afghanistan has been the main focus of the training we have done for the past year and half prior to our deployment, but we are ready to do the full line from presence operations to major contingency operations," said Commander Timothy M Hill, executive officer of the strike fighter squadron. But what may be perceived by some as a brilliant spectacle as the aircraft take off and land on the carrier could also be perceived as provocative manoeuvres. Not that far from the carrier's bows lies the coastline of the Islamic republic of Iran, a potential American adversary and the subject of United Nations' sanctions for its alleged pursuit of nuclear weapons.

Capt Clarkson is acutely aware that Iranian fast-attack ships and torpedo boats roam the area. Just as US military personnel ready for battle, so too do the Iranians. On several occasions in recent years - including when Revolutionary Guards captured 15 British military personnel who were operating in Gulf waters in 2007 - tensions between the West and Iran have nearly turned unfriendly encounters into deadly confrontations.

"I certainly do not expect a clash," said Vice Adm Mark Fox on July 5 as he assumed command of the 5th Fleet in a ceremony in Manama. "We are not in the business of looking for trouble, but if trouble appears we know how to deal with it." @Email:[e-mail]