Two Republic of Korea Air Force F-15Ks, two Japan Air Self-Defense Force F-2s, and two U.S. B-1B Lancers are training over the ocean near the Korean Peninsula. /Courtesy of U.S. 7th Air Force

On the 15th, a Russian military aircraft entered the Korean Air Defense Identification Zone (KADIZ) prompting a military response.

According to the Joint Chiefs of Staff, around 9:20 a.m. that day, several Russian military aircraft sequentially entered the East Sea KADIZ before quickly deviating east and north of KADIZ, with no violations of airspace reported during this process. The military had identified the Russian aircraft before they entered KADIZ and deployed Air Force fighters to implement tactical measures in preparation for any contingency.

The Joint Chiefs of Staff noted, "As a result of communications with the Russian side, it was confirmed that the purpose was training and there was no intention to violate airspace."

A Russian military aircraft also entered KADIZ with a Chinese military aircraft last November before deviating. An air defense identification zone is an arbitrary line established to identify military aircraft approaching a country's airspace early and respond accordingly, which is a different concept from a country's sovereign airspace.

However, it is international practice for military aircraft entering another country's air defense identification zone to submit flight plans in advance and notify the position upon entry.