Chinese state media outlets have responded to news of potential joint U.S.-Japan operations in the disputed South China Sea with a spate of fiery editorials, but experts say Japan's announcement of increased engagement in the waters breaks little new ground.

State media outlets said Saturday that any joint U.S.-Japan patrols in the South China Sea could prompt Beijing to beef up its military deployments in the hotly contested Spratly Islands — and ultimately set the stage for an air defense identification zone (ADIZ) declaration.

The reaction comes after a speech Thursday by Defense Minister Tomomi Inada to a Washington think tank in which she said Japan would "increase its engagement in the South China Sea through ... Maritime Self-Defense Force joint training cruises with the U.S. Navy."