Well, Japan wanted various concessions commercial, diplomatic, and territorial from China. In particular the Army wanted to get what it wanted. If not Marco Polo, then something else...Japan was going to keep pushing until it got what it wanted either through Chinese agreement or military action. China's problems in terms of resisting Japanese military action were really not going to get much better any time soon. They may have some more better trained troops, some more equipment but the basic issues with the Chinese military and the Chinese government won't go away.