TOKYO — Military legislation passed by the Japanese Diet on Sept. 19 will allow the country to expand operational assistance to allies involved in foreign conflicts . Though it still limits assistance, the bill basically overturns Japan’s traditional self-defense policy and allows it to act in "collective self-defense" with partners. in partnership with allies.
 
Such assistance would include logistical support for allies fighting in foreign wars, providing air defense for US and allies facing enemy missiles, securing sea lanes and preserving freedom of navigation, participation in United Nations humanitarian/disaster relief operations, and allowing Japan to engage in armed hostage rescue missions. 
 
The key provision is that such contingencies will need to present a so-called "existential" threat to Japan's security, said Corey Wallace, security policy analyst at the Graduate School of East Asian Studies at Freie Universität, Berlin. "In reality, this probably means such increased freedom of action will be restricted to regional contingencies surrounding Taiwan and the Korean Peninsula and the US military activities pertaining to those situations."
 
"In one sense, this action by the Japanese government addresses some fundamental oddities in the US-Japan Mutual Security Treaty through a unilateral, domestic Japanese action, without going through the potential turmoil of a treaty revision," said Lance Gatling, Nexial Research, Tokyo.

"Again, the measures do not require Japan to act, but rather allow it the option to use military force for cooperative defense in appropriate situations."
 
Chikako Ueki, a specialist in international security at Waseda University, said the law is "quite flexible and worded to allow the government to have discretion, but the law was not explained in the National Diet to the public in such a way." She said it was explained that the Self Defense Force (SDF) would be used only in situations where Japan's own national security is at stake. In other words, Ueki said the definition of what constitutes an existential threat is up to the administration in power to decide.

"The public is quite opposed to a greater fighting role for the SDF, so at this point, it is unclear what Japan will do and will not do."
 
This has led to confusion in many quarters in the US defense community. Scenarios bandied about to help clarify when Japan might act be helpful include a role for the Navy when supporting US forces in a number of Northeast Asia contingencies, said Grant Newsham, senior research fellow at the Japan Forum for Strategic Studies.
 
Newsham said the Air Force would also be helpful, "especially if it figures out there is more to air defense than F-15s dogfighting at 30,000 feet." Ground forces will be helpful in certain contingencies, he said, such as amphibious operations in the Nansei Shoto "and even operating land-based anti-ship missiles as part of an effort to block off the channels between the Nansei Shoto islands."
 
Another One other example that stands out is the use of naval integrated fire control-counter air (NIFC-CA) by not only the Japanese armed services, but also between the Japanese SDF and the US Navy, Wallace said. Currently, integration of the SDF into the US' broader regional presence through cooperative engagement capability , an integrated fire control sensor network that works alongside NIFC-CA likely would be avoided. The reason, he said, is because it could result in the SDF providing targeting information to the US, or having to decide to eliminate a target itself based on information from the US without a direct attack having been launched against Japan. "This will no longer be the case."
 
The major problem at present is joint operations, Newsham said, and the US has to see real joint planning for specific contingencies and effort by the US and Japanese military to learn to operate together. The navies are already quite advanced in this regard, he said, "but the other US and Japanese services are not far along at all."

A fundamental problem that needs to be fixed is Japan's inability to operate jointly across all its services in "seamless cooperation," he said. At present, Japan's military services "can barely communicate with each other."
 
Jun Okumura, visiting scholar at the Meiji Institute for Global Affairs, Tokyo, said that the more important "effect of the change consists of the harder-to-define benefits that the joint exercises and drills that are required and the protocols, manuals and the like that must be worked out for that purpose."

This continuous process will more closely integrate the Japanese military with its US counterpart, and by extension, other US allies in the Asia-Pacific region, "with strategic and tactical benefits from Japan’s perspective that extends to joint operations elsewhere."
 
Political challenges remain. The real test of the legislation will be the future and the political will of those in power. Though the bill was passed by a majority of elected representatives in the Diet, there is still domestic opposition from the public, as illustrated by large protests during the debate in the Diet before passage. 
 
If Japan attempts to confine its efforts under the new legislation to providing only logistical support to US forces during wartime, "it will be a disappointment," Newsham said — particularly, as the region changes under growing Chinese military power and the US begins to tighten its financial belt.

"Japan has always been able to do whatever it wants to do defense-wise," he said. "It's just never had to do so much owing to the US providing so much defense coverage."

Now the US and Japan face a real adversary capable of dominating the region and displacing the US. Japan must begin working closer with the US and take more responsibility for its own defense.

Wendell Minnick contributed to this report from Taipei.