Right now there is a lot possible starting point of world war III.
1..Japan and China >sinkaku islands,  rich in oil and gas.
2. China & Taiwan and Philippines> panatag shoal and spartly islands both rich in oil and gas, Us will be drag because of mutual defense treaty.
3.NorthKorea, its brewing. In times of war 90 percent possibility china will help north korea.
4. If Israel attacks Iran. US and Russia possible china will be drag  to war because its one of their biggest oil supplier.
5. Syria. If Israel attacks Syria. Russia and US will be drag to war.