You will start off in a plane. Start running forward and jump out of the plane.
Land on the USS Valkyrie.
After landing on the ship, start killing the enemy soldiers on board.
Once you've dealt with all the enemies, follow your teammates inside the ship.
Make your way through the narrow hallways and find Captain Gerrison.
After regrouping with Captain Gerrison, you will have to open the metal door and let the Chinese soldiers inside the room.
The man with the covered face is going to reveal his identity to the Chinese soldiers, which will stop them from attacking you.
Follow your teammates down to the boat with explosives on.
After getting on the boat, make your way to Chang's ship.
Irish is going to plant an explosive charge on Chang's ship.
Once the explosives are planted, shoot your grappling hook up on the bridge using your rope gun and make your way up.
After making your way up, you will have to make a decision. You will have to choose between Hannah or Irish and sacrifice their lives to get back down and plant the C4 explosive charge, or you could choose to sacrifice the entire Valkyrie ship and save your teammates. After deciding what to do, the game will come to an end.
Once you've chosen what to do, the credits will appear.
That was my Battlefield 4 walkthrough guide, I hope you found it helpful.