several european powers had control of other parts of asia by the 1900s, such as british india, french indochina and portuguese macau and goa. russia and britain struggled for power in the central asian region in the nineteenth century. the trans-siberian railway that crossed asia by train was complete by 1916. parts of asia remained free from european control, although not influence, such as persia, thailand and most of china. in the twentieth century, imperial japan expanded into china, korea and southeast asia during the second world war. after the war, many asian countries became independent from european powers. during the cold war, the northern parts of asia were communist controlled with the soviet union and people's republic of china, while western allies formed pacts such as cento and seato. conflicts such as the korean war, vietnam war and soviet invasion of afghanistan were fought between communists and anti-communists. in the decades after the second world war, a massive restructuring plan drove japan to become the world's second-largest economy, a phenomenon known as the japanese post-war economic miracle. the arab-israeli conflict has dominated much of the recent history of the middle east. after the soviet union's collapse in 1991, there were many new independent nations in central asia.