The jamming in itself is an obvious sign of Alliance airspace being breached. Dozens of IFX-25 fighters scour the skies over Munich and surrounding areas. Large, slow B-2 bombers are easily detected once the fighters get close enough for their radars to burn through the jamming. Once detected, the task of getting rid of the bombers is as simple as a couple bursts of 25mm cannon fire.
An announcement from the Alliance Ministry of Foreign Affairs: The Celatoroan Rangers detained in Munich were aboard a civilian airliner taking them back to Celatoro. The next time Celatoro meddles in Alliance affairs, the punishment will be far worse than a single dead Ranger.