The U.S. military has conducted a major joint exercise in the western Pacific ocean. The exercise comes amid rising concern about encounters involving China and other countries in disputed waters of the East and South China Sea, and airstrikes against Islamic militants in Syria.
As the U.S. military prepared for an air strike on Syria, more than 18,000 personnel from the army, navy, air force and marine corps on Tuesday wrapped up participation in the U.S. military's largest joint exercise, a nine-day drill held in the western Pacific.
Named Valiant Shield 2014, it also included two nuclear-powered aircraft carriers, 19 surface ships, an undisclosed number of submarines and more than 200 aircraft.
Cruisers at sea fired missiles, adding a realistic element to the air-sea battle concept, which aims to overcome enemy attempts to deny access and maneuverability within sea lanes and air space. Both China and Iran, in their recent military doctrines, have emphasized such strategies.
The drill also included some activities on land, including Guam Army National Guardsmen defending the island of Tinian (in the Commonwealth of the Northern Marianas Islands) from "invading" infantry marines flown in by MV-22 Osprey tilt-wing aircraft.
Sea drill challenges
The operational commander of the exercise, Navy Rear Admiral Mark Montgomery, said conducting a combined drill primarily at sea is more challenging than one on land because of reliance on long-range communications. But, he said, "the command-and-control element held together tightly."
Speaking to VOA News from the USS George Washington aircraft carrier, the commander explained this latest Valiant Shield exercise included new elements.
"We tested new tactics, techniques and procedures for long-range engagements or for search and detection of adversary combatants that proved successful," said Montgomery.
Montgomery, who is commander of Battle Force 7th Fleet, also confirmed there was a significant cyber component to the war game.
"This is my third Valiant Shield and the first one where I've seen this kind of cyber-play. And I think it's indicative of the fact that this is a growing domain for us, particularly something that we have to ensure that our defenses are properly aligned and one where you have to integrate the affects we're achieving on the offensive side," said Montgomery.
A Chinese auxiliary spy ship was nearby in the U.S. Exclusive Economic Zone while the exercise was underway off the Pacific island of Guam.
The commander notes that did not come as a big surprise.
"We had no problem with it. In my mind all the operations were safe and professional between the ships. But clearly it was here to observe, monitor and collect on the U.S. training event," said Montgomery.
The drill, held every two years, began on a somber note. In pre-exercise operations two F/A-18 "Hornet" jets, attached to Carrier Air Wing 17, collided in flight on September 11 about 460 kilometers west of Wake Island. One pilot was quickly located and returned for medical attention to the USS Carl Vinson aircraft carrier. The other pilot is presumed to have died.
China tension
China's territorial claims, which conflict with other countries in the East and South China seas, have led to increased tensions in the region. The United States is bound by treaties to defend two of those claimants - Japan and the Philippines - if they are attacked.
The U.S. Defense Department said a Chinese fighter jet came within six meters of an American navy plane last month, about 215 kilometers east of China's southern Hainan island.
China's naval commander has vowed to continue intercepting such U.S. military aircraft conducting close-in surveillance.
A Pentagon assessment, released three months ago, characterized China's air force modernization as "unprecedented in its history" and concluded China is rapidly closing the gap with U.S. and other western air forces "across a broad spectrum of capabilities."