Prime Minister Junichiro Koizumi’s pledge to keep the Self-Defense Force troops deployed in Iraq after a scheduled end-of-June transfer of power to an interim government will open a new chapter for the SDF.

Koizumi made the pledge Tuesday during talks with U.S. President George W. Bush on Sea Island, Ga., on the sidelines of the annual Group of Eight summit. The SDF has been under scrutiny since its creation due to the nation’s war-renouncing Constitution.

The United Nations Security Council adopted the same day a new resolution authorizing a U.S.-led military force to “take all necessary measure to contribute to the maintenance of security and stability in Iraq.”

Koizumi’s statement was widely seen as an effective promise of the SDF’s participation in a multinational force, the first such role in the SDF’s 50-year-history.

“That would be a deviation from the government’s traditional interpretation of the Constitution that has guaranteed the nonuse of force when (the SDF) participates in U.N.-backed peacekeeping missions,” said Tetsuo Maeda, a security expert and professor at Tokyo International University.

“This isn’t something you just tell the leader of the United States,” he said. “Why didn’t he follow the due process of explaining to the Japanese people (the decision) and then report it to the United Nations?”

The government says that the humanitarian nature of Japan’s mission in Iraq, currently overseen by a 500-strong contingent of Ground Self-Defense Force troops in the southern Iraqi city of Samawah, will not change.

To back this argument, the Foreign Ministry has cited a provision in the newly adopted U.N. resolution calling on member states to contribute to the multinational force for “humanitarian and reconstruction assistance” as well as for the security and stability of Iraq.

Participation in the multinational force is deemed necessary for Japan to have the SDF continue its mission in Samawah.

Any country wanting to do so outside the multinational force would need to sign a Status of Forces Agreement with the new Iraqi interim government, because the current one with the Coalition Provisional Authority, the U.S.-led caretaker administration, will expire when the CPA dissolves on June 30.

But a collective green light for the foreign forces currently in Iraq to stay came Wednesday, when the Security Council unanimously voted on the new resolution to authorize the presence of the multinational force “at the request of the incoming Interim Government of Iraq.”

The problem for Japan will be how to make sure that the SDF, as part of a multinational force, will not be involved in the use of force.

The new resolution authorizes the U.S.-led multinational force to maintain security and stability “under unified command,” but a special Japanese law enacted last year for the SDF dispatch to Iraq only allows the SDF to engage in humanitarian and noncombatant missions.

Whether the SDF can be independent from that unified command “is the key point and will need further discussion after prime minister’s return,” Chief Cabinet Secretary Hiroyuki Hosoda said Wednesday.

“When you become part of a certain framework, you have to follow its practices,” said Admiral Toru Ishikawa, Chairman of the SDF’s Joint Staff Council. “But I understand that each force will carry out its mission under the orders of its government.”

When Japan formally commits to joining the multinational force, the government will explain how the move relates to the new U.N. resolution and the Constitution, as well as the relationship between the SDF and the multinational force, he said.

Japan has gone through the same struggle time and again over the past decade, often accompanied by esoteric explanations, to ensure that SDF troops dispatched overseas will not be called on to use force.

When a law allowing the SDF to join U.N.-backed peacekeeping missions was enacted in 1992, it was said that the U.N. peacekeeping force was “totally different from a military force as is commonly known” because it was acting neutrally and not in a forceful manner.

In joining the U.S-led antiterrorism mission in Afghanistan in the wake of the Sept. 11, 2001, terrorist attacks in the U.S., Japan said the SDF would offer only “logistic support in places that are not battlegrounds.”

And in making the decision last year to send troops to Iraq — the first SDF mission in a country still experiencing conflict — it came up with the concept of a “noncombat zone,” a term attacked by the opposition camp as a fiction, given the reality of continuing insurgent attacks in Iraq.

“What to do with the SDF should be a subject to be widely debated as a constitutional matter,” said Maeda.

Koizumi’s remark to Bush, however, bypassed any such debate, he said.