The United States and Australia announced a mutual defence treaty that declared a cyber attack on one would result in retaliation by both nations; this new agreement appears to be the first instance of a mutual defence treaty in the cyber realm.

The latest announcement comes as an addition to the Australia, New Zealand, United States Security Treaty (ANZUS), which commits the three nations to support one another if one is attacked. The treaty, signed 60 years ago, now includes cyber attacks as well as physical attacks. Beginning in 1985, New Zealand has not been an active partner of ANZUS.

Secretary of Defense Leon Panetta said the treaty highlights how the United States perceives cyber threats. “We’re all going to have to work very hard not only to defend against cyber attacks but to be aggressive with regards to cyber attacks as well. And the best way to accomplish that is not only on our own but by working with our partners.”