He joined Korean war as the commander in chief of Chinese army. He wisely caught the weakness of US Forces and swiftly used it at the earlier stage of Battles. But as times went on,
the strength of US Forces frustrated him. He pointed out 3 things – systemic supply & logistics, well combined ground forces– air forces co-operation and powerful fire supports.
After the fail of the 4th Offensive to deprive Seoul in Apr 51, He gave up winning in the Korea war and turned into his main military strategy. He ordered Chinese army to dig the trench line along to the first frontier line. It almost 250km long and 20-50km wide. They kept all weapons and soldiers inside trenches in usual time. And used them for night attack.
He signed the ceasefire agreement on 27th July in 1953 as commander in chief of Chinese army.