The bad news first. The Peoples Republic of China now believes that it can successfully prevent the United States from intervening in the event of a Chinese invasion of Taiwan or some other military assault by Beijing.
Now the good news. China is wrong.--And for one major reason.It apparently disregards the decisive power of Americas nuclear-powered submarines.
Read more here: China thinks it can defeat America in battle - The Week
The USA will remain the only real world power for the foreseeable future.
And one of the main reasons for that is its submarine fleet.