Since the Battle of Jingxiang, Li Tang's situation has completely deteriorated day by day.
In the battle of Jingxiang, Li Shimin was defeated and lost more than 100,000 troops. Of the 170,000 troops, less than one-third returned to Bashu. Moreover, after this battle, there was only one Li Tang left in the world, and Li Tang no longer had the ability to counterattack the Sui Dynasty