Will Japan Embrace the “Illegal But Legitimate” View of the UN Charter’s Limits on Use of Force?

Japan has been slowly moving to modify its domestic law, both constitutional and legislative, restricting the use of its military forces outside of Japan.  In its latest political discussions, it is worth noting that Komeito, a partner to the ruling Liberal Democratic Party, has been insisting on the three “Kitagawa” principles as a basis for any new law governing the use of force overseas.  The three principles are: “legitimacy under international law, public understanding and democratic rule, and ensuring the safety of SDF personnel.”

Interestingly, the ruling party has been hesitant to fully embrace the “legitimacy under international law” requirement, which might be read to require UN Security Council authorization for most overseas uses of military force. Noting that China has a veto in that body, ruling party lawmakers would like to make sure “legitimate under international law” is given a broader meaning.

“In terms of international law, legitimacy isn’t necessarily limited to [those situations involving] a U.N. resolution,” said a senior LDP official. “We’d like to discuss what cases would be legitimate.”

The US and Western powers have used this “illegal but legitimate” analysis to justify actions in Kosovo and elsewhere.  It will be interesting to see if Japan eventually adopts some version of this approach.  It would be wise to do so from a practical perspective, since many scenarios where Japanese forces would act “overseas” including the Senkakus, Taiwan, Korea, or Syria may not qualify as “self-defense” under the U.N. Charter.  But such a move would chip away again at the UN Charter’s limits on the use of military force.