In the nineteenth century, the Industrial Revolution gave European nations industrial and military power so much greater than the non-European world that by the beginning of the 20th century Europe had essentially conquered the planet. If you’d asked someone in 1910 to predict what would happen to Africa, Asia and the Middle East, they would probably guess that those regions would be controlled by the European powers indefinitely, or at least until some time in the future when they had “advanced” enough to become semi-independent members of European led commonwealths.
Then, when the European powers seemingly had the world on a platter, they engaged in the useless, pointless fratricidal World War One. Although this didn’t immediately cause the collapse of colonialism, it ultimately caused the the creation of two radical powers- Nazi Germany and the Soviet Union. Nazi Germany started the second World War, which irretrevably weakened Britain and France, the two main imperial powers. It also transformed the Soviet Union, a radical anti-Western regime, into a world power. The Soviet Union was both able and willing to subsidize the Third World nations with armaments, and in a scant 15 years the British and French empires dissolved.
In a sense one could claim that colonialism died a premature death, due to a combination of unfavorable circumstances. But now with the Soviet Union gone and the United States acting like a hegemon, are we moving back towards the domination of the third world by the West? Perhaps not in the sense of classic colonialism, but more in the sense that the US and it’s allies will exercise control over the third world nations by force or the threatened use of force.
Please note that I am not claiming that this would be good or right; merely that in terms of pure power politics, this seems to be the direction we’re headed.