Pandora's Box was a mythical container of plague, sorrow, poverty, crime and hope. Pandora opened the box and released everything but hope.
In 2372, Benjamin Sisko told Admiral Leyton that if the USS Lakota fired on the USS Defiant, a Pandora's Box would be opened, one that would be impossible to close. Leyton later told him "this Pandora's Box of yours, we're opening it together". (DS9: "Paradise Lost")