I feel that we are agreeing more than we differing.
When you pointed out "1 billion" of today's China, I believed that you were making the point that today's particular reemerging of China is unique, not only in the world, but also unique to China.
My point was that in relative terms, this time of reemerging is not that unique in China. If 1 billion (should be 400 million at 1949 when the reemerging began) today is unique compared with the rest of world, then 65 millions of reemerging of Ming in 1393 (to eventually 160 millions in 1600s) compared with the rest of world population in 1393 was also unique (but not to China herself as it has repeated many times before that time).
My bottom line is that, things change all the time, the bar keeps going upwards, today is always "unique", but today's "uniqueness" will become just another repetition some hundred years later, therefor not unique any more. I always see China and maybe the whole humanity's going forward as a spring (the device). It repeat itself to the same but not same place, every time to a higher/further point but over the same point.
The reemergence of China today is unique, even compared with what historians know of ancient China. Previous falls didn't lay China so low as to be substantially below the world's average, because past falls were mainly government changes, while the common folks lived pretty much as before. Only their overlords changed.
Contemporary China suffered immense body blows from westerners to the point where central government basically lost sovereignty of many of its coastal cities. Westerners forced Unequal Treaties down China's throat with right by might. Those people robbed, looted, raped, and murdered with glee, and Chinese public became second-class citizens in their own country.
As the Qing Dynasty struggled to recover from the white scourge, Imperial Japan attacked in 1894. Losing to Japan did as much to end the Qing Dynasty as Sun Yat Sen, because no Chinese government can rule if it can't secure Chinese civilization and sovereign territory. The Mandate of Heaven was withdrawn.
Republic of China went all out to rebuild the government, put down warlords, initiate Sino industrial revolution, unite the country, and prepare for the Japanese invasion ROC leaders knew was coming. But, before China could make much headway, Japan attacked with full fury. Tojo said there would be no more China in 3 months, and Westerners agreed. The thought China could take on Japan alone for nearly 8 years didn't occur to those people. But fight China did, and long before Winston Churchill made his inspired speech "we shall fight on the beaches...; we shall never surrender," China showed you only surrender after you die.
The end of WWII brought no peace and recovery, as KMT and CPC continued its prewar struggle. Other countries in the world busied themselves recovering from the WW, and America created and lead a new world order at Bretton Woods. CPC won the civil war in 1949, established the PRC, and Mao said the Chinese people have stood up. Westerners were given the boot, and America lead the full containment of the PRC. Within a year, China fought US-lead UN forces in Korea, and missed another chance to recover from the ravages Britain started in 1820.
The armistice in 1953 did little to help China recover, as Mao's "Great Leap Forward" (1957-1960) failed to produce desired social and industrialization results. A great famine swept through China, and tens of millions died. The Cultural Revolution followed the GLF in 1966, and the country went backwards in development till Deng Xiaoping was brought back following Mao's death. But, before Mao died, he did China a great deed by accepting US primacy in Asia in return for support against the Soviet Union and end to isolation. There was also that bit about the Gang of Four, but it was minor inconvenience compared to what China has suffered from 1820 to 1979.
Taking advantage of America's offer to assist China, Deng finally opened China to the world in late 1979, and the country went on a three decade economic development and expansion the world has never seen before. No other country has come so far, so quick. China not only developed economically into the world's second largest economy by market exchange rates, it also lifted about a billion people out of abject poverty. The World Bank recently said China still has around 100 million people in abject poverty, and that's the bad news. The good news is 1.24 billion Chinese are no longer abjectly poor.
So, Taxiya, my apologies for such a long-winded reply, but I stand by my original statement: the world has never seen the reemergence of a great power like of China.