Question

But when the corn-lands had no more grain and all the Romans (Byzantines) had come into an exceedingly evil plight, they surrounded Belisarius and tried to compel him to stake everything on a single battle with the enemy (Goths), promising that not one of the Romans (Byzantines) would be absent from the engagement."
—History of the Wars, Book VI, Article III

According to the passage, why did the Byzantines want Belisarius to stake everything in a single battle against the Goths?