Not every big country in the world (I'm not talking specifically about your examples) has society that's sufficiently developed and sophisticated to pull off a modern XXI-century information age economy. In other words, it's not obvious that all the laggers will eventually (say within the next 50-100 years) catch up.
So, while they lost their head start, at least they have that...
However, painting the West’s ability to heap “unequal treaties” on China cannot reasonably be described as a function of finding and conquering the new word. Firstly: the major conquest of the new world came through Spain, which had little to no involvement in the humiliation of the Middle Kingdom. Second, colonies in North America did not give the British gunboats capable of demolishing the Chinese fleets.
The reasonable conclusion is that the Enlightenment and the scientific advances eminating from that allowed the West to go from isolated, low population minor powers into worldwide empires.
That's basically every body apart from the west.
Education was a very elite thing in most societies, even in the west too. But some thing very strange happened around Gutenberg's times and west was able to take advantage of that unique situation.
For example, there is no parallel of Renaissance or Industrial revolution in any non-western country. China comes close, but even then, not exactly.
That's one way to look at it. The other would be to yield to the continuum a bit, to see that growth (technological, military, economic) usually doesn't happen overnight. Even if Iran were on the cusp of again being a world power, it wouldn't happen overnight.
The industrial revolution pushed "the west" pretty far in terms of power/economics but there were thousands of years of human history prior to it. In that longer view of history, China has always been a major player, and the last 150-ish years have been a fluke that's being corrected.
But western journalism really treats everything prior to the industrial revolution as caveman times, meaning they'll be equally surprized seeing Iran (Persia), India, Turkey and others 'rise' up in the coming decades as well.