There is an "unspoken space race" among Asian countries that may fuel regional tensions and increase risk of space militarization, according to policy experts.

In a commentary published in the journal Nature, James Clay Moltz, an associate professor in the department of national security affairs at the Naval Postgraduate School in Monterey, Calif., wrote that even if the countries do not acknowledge it, an intensifying space race is under way place in Asia, and without greater cooperation, there is a risk for future confrontations among Asian space powers.

"I've spoken with officials in multiple countries, and it's very clear that, even if they're not willing to say so, they're watching what their neighbors are doing very carefully, and they're concerned about relative prestige," Moltz told Space.com.

Among the Asian countries that have been steadily expanding their orbital operations are China, Japan, India and South Korea, with China at the forefront.

In 2003, China launched its first manned spacecraft, Shenzhou 5, making it only the third country, after Russia and the United States, to independently launch a human into space. This served as a wake-up call for other Asian spacefaring nations.

This was followed by two more manned missions in 2005 and 2008, and in September 2011, the country launched its first unmanned prototype space lab module, the Shenzhou 8, into orbit and completed two separate docking tests in November. The success of Shenzhou 8 will pave the way for China's goal of constructing a manned space station in orbit by 2020.

Closely following China are Japan, which is a member of the International Space Station and has supplied astronauts for 15 missions since 1992, all aboard American or Russian vehicles; and India, which has also launched satellites and space observatories and its own rockets and has announced its goal of sending its own astronauts into space next year.

Meanwhile, Malaysia, Indonesia, Thailand, Vietnam and Taiwan are also expanding their space capabilities, Moltz said.

According to Victoria Samson, Washington Office director of the Secure World Foundation, an organization dedicated to the peaceful use of outer space, Asia's space activity is part of a larger trend, as more and more countries around the world are realizing the benefits of an active presence in space.

However policy experts are concerned with the fact that Asian countries tended to conduct their space activities independently, unlike the European Space Agency, which was established in 1975 and has 18 member states.

"Where there's close cooperation in ESA, there's very little peer-to-peer cooperation in Asia," Moltz said. "Asia really stands out as countries that are pursuing nationalistic policies in space. The major spacefaring nations in Asia simply don't cooperate, and I think that's a real problem. They also don't have a tradition of engaging in regional security dialogues and arms control. If the current Asian space race turns more into a military space competition, I see great instability."

The space race in Asia is fueled in part by long-standing geopolitical feuds, Moltz said. By pursuing competing national agendas, these countries are not only raising regional tensions, they are also fostering scientific duplication rather than sharing costs and pooling resources.

Greater cooperation and dialogue between Asian spacefaring nations could stem this increasing tide of space militarization and promote future partnerships toward shared goals, the policy experts said.