The participants of the largest annual multinational military exercise in the Indo-Pacific, Cobra Gold, gathered for the opening ceremony in Thailand on Tuesday. This year will see a substantial increase in US troops participating in the drills, with its contingent amounting to 6,800 - nearly double last year's number. More than 11,000 service members from 29 countries are taking part in the event co-sponsored by Thailand and the United States. A total of seven countries enjoy full participation: the US, Thailand, Singapore, Japan, Malaysia, South Korea and Indonesia.