Last months submarine accident, which left 70 sailors dead, has resulted in the dismissal of many senior naval officers. These include the head of the navy, and  his political officer. The commander of the Northern Fleet, and his political officer, were also dismissed. The Chinese borrowed the concept of the political officer from the Soviet Union. The political officer represents the Communist Party and has the authority to overrule any order a military officer gives. In reality, the political officer often acts as a combined morale and special events officer. The political officers are primarily responsible that nothing happens in their unit that would embarrass the party. In theory, political officers are supposed to prevent their commanders from getting involved in fiscal corruption, but often it's the other way around, with the political officers getting involved in illegal money-making schemes. Another policy adopted from the Soviets is the "vertical chop". If something happens that makes the government look bad, the most senior commanders take the fall. Actually, this is something of an ancient Chinese custom as well (except that in the old days, the senior guy would literally lose his head, as would his entire family.)