Anyone asking this question today got to have his head check. I just read it somewhere that one pseudo western scholar did asked this question. My simple answer, the person asking this question is basically a D grade student or D grade scholar and did not know what he is thinking, or still living in his own world of make beliefs. A hillbilly of sort.
The American strategy at one time was to contain China within the first island chain, stretching from Japan down to Taiwan and the Philippines. The Americans then were the most powerful sea and air power to be able to do that. And China was still militarily very weak vis a vis the Americans, particularly in air and sea power. No Chinese ship can ever think of sailing further than the first island chain if the Americans did not want it to do so.
The whole western Pacific, all the seas surrounding China, were as good as an American lake. The American navy and air force were the undisputed and unchallenged masters of this lake. Chinese ships would be contained within the first island chain, China would be contained within the first island chain in the event of war or hostility. And the Americans could sail their aircraft carriers to the door of China any time they wished in a show of force, through the Taiwan Straits, and China could do nothing about it.
That was 20 years ago. China took the humiliation in the show of force but did not sit idle. They went on to develop a new military strategy called Anti Access, Area Denial Strategy, to deny and stop the American warships from entering the area bounded by the first island chain and also the second island chain that extended further to Guam in the Pacific Ocean. For this strategy to be effective, China must develop weapons to threaten American warships in the area. China came out with DF21 and DF26 anti ship and anti aircraft carrier missiles with range of 2,000 km to 4,000 km from its shores.
With these missiles and other complements of war, submarines, bombers, drones, warships etc etc, China today is in control of all the seas around its coast lines, extending 4,000 km outwards. Any warship within this range is a sitting duck and would be killed when war breaks out. China has turned its coastal seas, the Yellow Sea, East China Sea and South China Sea into a China lake.
The question of, can China breaks out of the first island chain, is moronic, obsolete today. A better question, would American ships be able to enter the China lake, ie the seas within the second island chain without being sunk by China. The so called American fantasy of freedom of navigation trips around the South China Sea is only possible in peace time, when China does not press the buttons. No thinking American commanders would dare to risk an aircraft carrier with 7,000 men and 100 aircraft or American warship in the China lake in times of war. They would stay far far away from the striking range of Chinese missiles for safety. The China lake would be for Chinese ships to patrol and guard against enemy ships.
Now, who's that asking if China can break out of the first island chain? Need to see a shrink and has his head checked. The military might of the Americans is still as before. But the military clout of China has grown beyond recognition and could keep the American ships out of the western Pacific Ocean, out of the China lake, no longer able to cause mischief in China's court yard, in China's lake.
Actually the range of Chinese missiles now encompass the Indian Ocean as well. Don't fool around with the Chinese missile and air defence system.