It's a feel-good mission that also helps the U.S. achieve political aims, namely deepening three-way cooperation with close allies Australia and Japan, who are first-time participants. Analysts say the U.S. has been boosting the trilateral relationship in recent years as it keeps an eye on China's growing military.

 

The boxes include books, canned food and items like fishing nets that will help islanders maintain their largely subsistence lifestyle. This year, each package will also include a soccer ball.

Many islands are tiny. Fais Island, for example, has just 300 inhabitants. It's less than 2 miles long and a mile wide.

The planes fly low, look for a safe spot to drop the bundles then release them from the back of the C-130s.

"It's from 300 feet and 130 knots, but you feel a kinship with these folks when you see them on the ground waving," said Col. Douglas C. DeLaMater, the commander of the U.S. Air Force's 374th Airlift Wing.

University of Guam distance education staff use ham radios to talk to the islanders throughout the year and relay their needs. Most recipient islands are the same each year.

U.S. Air Force Brig. Gen. Gregory Guillot, who is the director of strategic plans at Pacific Air Forces, said the Christmas Drop offers a good trilateral training opportunity, particularly in a time of budget constraints and busy units.

Japan and Australia each sent one C-130 to join three from the U.S.

Guillot said the three air forces have been increasing their cooperation, noting they also come together for the annual Cope North exercise on Guam and Red Flag drill in Alaska. Inviting Australia and Japan to Christmas Drop was a logical extension of other work the countries have been doing, Guillot said.

"Partnerships here in the Pacific are the key cornerstone in our strategy to maintain regional stability and prosperity. Japan and Australia share a common interest in that goal," Guillot said.

Brad Glosserman, executive director of Pacific Forum think tank in Honolulu, said the three-way relationship is the "gold standard" for the U.S. military's strategy toward allies in the Pacific. The U.S. wants to break out of "hub and spoke" system of bilateral alliances it has with five Asian countries and link multiple allies together, he said.

The U.S. has tried something similar with South Korea and Japan, but this grouping has struggled amid tensions in Tokyo and Seoul over Japan's past colonial rule of Korea.

The improved military capabilities of U.S. allies are a factor driving the increased cooperation, as is China's rise as a military power, Glosserman said.

Trilateral links can bring together like-minded U.S. allies in support of freedom of navigation, the peaceful resolution of disputes and other principles, Glosserman said. The U.S. and China have disagreed at times, for example, on matters like which waters U.S. Navy ships may pass through.

"The argument is that we're not taking sides against that country, but we are defending very, very powerful and important international principles," Glosserman said. "The larger the coalition of forces that are behind that, the more effective that position."