The air defense identification zone (Adiz) is a perimeter in which air traffic is monitored by the army of one or more countries, beyond its national air space, to provide reaction time additional in case of hostile maneuver.
The United States has established four, but a dozen other countries have also created their own. That of Alaska extends up to approximately 320 km from the coast.
On May 29, the Russian Defense Ministry released images of two American B-1 bombers intercepted by Russian air defense after flying over the Baltic and Black Seas near Russia.
The duty Air Defence Forces in the Western and Southern military districts promptly revealed the actions of B-1B strategic bombers of the US Air Forces over the neutral waters of the Black and Baltic seas and conducted their escort by Russian fighters. https://t.co/Ef8kWkZ7OM pic.twitter.com/pCXLyh6VUa
— Минобороны России (@mod_russia) May 29, 2020