On the 18th of October (see Story Timeline), Russia accused Academy City's science as the cause of global warming and extinction of many animal species, and gave Academy City 24 hours to comply to its demands of surrendering all its technology to Russia help fix the situation. If Academy City refuses Russia will bombard the city with inter-continental missiles. The same will apply to all allies of Academy City, where Russia will attack with all their might "for the sake of the future of all mankind". An ultimatum that would last until midnight of October 19 (Russia local time) was given by President Soldier I. Krainikov, one which would be left unanswered.
Due to Academy City's lack of actions in Russia's declaration of war, the Third World War officially breaks out. Russia attempts to overwhelm Academy City with the massive amount of military resources they have, but as of October 30th, Russia is at a disadvantage and cannot break through Academy City's defense. Due to the superiority of Academy City's HsF-00 supersonic fighter aircraft, the Japan Sea remains under Academy City's control.
During the aerial skirmish, pilot and Anti-skill member Kameyama Ryuuta completely outclasses Russian pilot Ekalielya A. Pronskaya before finally planning to destroy the Russians by using the built-in laser weapons in the HsF-00.
- Anime: Toaru Majutsu no Index III Episode 18 (Proclamation of War)
- Manga: N/A
By order of appearance
- Airspace about Sea of Japan
- The Pugachev's Cobra is an aerial maneuver wherein an aircraft traveling at moderate speed lifts its nose for a short duration before returning to normal position.
- Kameyama Ryuuta: "You can’t escape from something moving at the speed of light. Prepare yourself, young lady, because I’m going to gently shoot you down."