There is no war in Ba Sing Se

There is no war in Ba Sing Se. Except, there is. The phrase originates from the American anime Avatar, in which Ba Sing Se is secretly taken over by the Fire Nation. As propaganda, guides are brainwashed into saying, "There is no war in Ba Sing Se" whenever questioned about a possible war.

It is used in real life to satirize and joke about propaganda.

"Russia is not at war with Ukraine, as there is no war in Ba Sing Se."
"The economy in the US is fine, there is no war in Ba Sing Se"