In a shift away from its postwar pacifism, Japan's (search) government overhauled its defense guidelines Friday, easing an arms exports ban and singling out North Korea (search) and China as security threats.

The overhaul, which also allows the government to develop a missile defense program with the United States, has raised concerns about a slow erosion of the pacifist society Japan built after World War II (search).

The opposition Social Democratic Party, one of the smallest parties in parliament, criticized the government for removing self-imposed controls on military development.

The changes also have been watched uneasily by some of Japan's Asian neighbors, who suffered under Tokyo's expansionist policies in the first half of the last century. The guidelines sought to allay such fears, saying Japan's military would not go on the offensive.

"Our country, under our constitution, will adhere exclusively to self-defense," the report said. "Following our policy of not becoming a major military power that would pose a threat to other countries, we will secure civilian control."

The plan, approved in a Cabinet meeting Friday, also calls for Japan to participate in international peacekeeping missions, underscoring Tokyo's efforts to play a global security role that better matches its economic strength.

The revised guidelines fits with Japan's decade-long effort to increase security cooperation with the United States. The pro-U.S. government on Thursday approved a one-year extension of the military's humanitarian mission in Iraq.

The government also authorized an ease to a longtime ban on arms exports to allow for the missile defense program with the United States. The guidelines cited the threats posed by North Korean missiles, China's military buildup and terrorism.

"This is about ensuring security and dealing with new threats as the times change," Prime Minister Junichiro Koizumi told reporters.

Pyongyang became one of Tokyo's biggest security worries after it test-fired a long-range ballistic missile over Japan in 1998, prompting Tokyo to begin researching missile defense. North Korea also has an active nuclear weapons development program.

Japan has maintained an arms export ban since 1976. Chief Cabinet Secretary Hiroyuki Hosoda said the government, however, would make exceptions to pursue missile defense with Washington for security purposes.

Ken Jimbo, director of the Japan Forum on International Relations, said the plan signaled that Japan's defense policy was adjusting to a post-Cold War world.

"It's epoch-making that the guidelines now call for a flexible, multi-faceted military instead of the stiff military foundation that's been in place until now," said Jimbo.

The guidelines vowed to maintain the current policy of not making or possessing nuclear weapons. Japan is the only country to have been attacked with nuclear weapons, when the United States twice hit the country in 1945.

The new defense outline, which covers from 2005 to 2014, also singles out China as a security concern, pointing out that Beijing has expanded the range of its military activities at sea and has been modernizing its naval and air force.

Hosoda played down the reference.

"It does not mean that we consider China a threat," Hosoda said at a news conference.

Japan's navy went on alert last month when a Chinese submarine was detected in the country's waters between the southern island of Okinawa and Taiwan. Japan says that China apologized, but tensions remain high.

Jimbo said the new guidelines would likely irritate Beijing but that Japan would also be seeking to deepen ties with its neighbor even as it follows the plan.

"China will undoubtedly express displeasure with the guideline revisions, but Japan can also cooperate with China by expanding exchanges," Jimbo said. "It's a two-pronged strategy."

The new guidelines followed Tokyo's extension Thursday of its largest foreign military operation since World War II. Japan currently has 550 ground troops in Iraq on a humanitarian mission to purify water and rebuild infrastructure. The mission follows the dispatch of the navy to provide logistical support to forces fighting in Afghanistan, a mission launched in 2001.

Acknowledging the budget pressures Japan will face as its population rapidly ages, the guidelines call for cutting the number of ground forces and tanks. The ruling Liberal Democratic Party on Thursday approved a 3.7 percent cut in defense spending.