Secretary of State Mike Pompeo said that a cyberattack could, “in certain circumstances, constitute an armed attack under Article 5 of the U.S.-Japan Security Treaty,” and that the United States would defend Japan in that circumstance.
The comment was made during a joint press availability on April 19 with Acting Secretary of Defense Patrick Shanahan, Japanese Foreign Minister Taro Kono, and Japanese Defense Minister Takeshi Iwaya.
Pompeo said that the U.S. and Japan have affirmed that international law applies in cyberspace, which is the grounds he uses to say that a cyberattack could be viewed as an armed attack under the U.S.-Japan Security Treaty.
Under Article 5 of the Treaty, which was signed in 1960 following the allied occupation of Japan after World War II, both the United States and Japan agree to recognize that “an armed attack against either Party in the territories under the administration of Japan would be dangerous to its own peace and safety and declares that it would act to meet the common danger in accordance with its constitutional provisions and processes.” Essentially, the United States agrees to help defend Japan from any armed attacks.
During the larger meeting between U.S. and Japanese leaders, Pompeo said that both parties “stressed the need to work together to protect classified information, maintain technological superiority, and preserve our shared defense and economic advantages from theft and exploitation.”
Shanahan seemed to concur with Pompeo, saying, “As we look to the future, however, we cannot only think in terms of geography, for emerging domains transcend borders. Cyberspace and outer space know no geographical bounds … And while cyber, like space, carries enormous potential, it also is a vulnerability. These domains are absolutely critical for securing our future, and we are not sitting back while our Chinese and Russian counterparts or competitors aim to disrupt and weaponize them. These domains offer real opportunities for alliance collaboration.”
Iwaya expressed Japan’s agreement with Pompeo’s conclusion, “We also agreed to enhance collaboration in the cyber area and confirmed that cyber attacks could constitute an armed attack for the purpose of Article 5 of the U.S.-Japan Security Treaty.”
While all parties involved agreed that cyberattack may constitute an armed attack under the treaty, no one offered any additional information about which attacks would be viewed as an armed attack and which would not.