Here is the story:
Genesis 11
The Tower of Babel
1 Now the whole world had one language and a common speech. 2 As people moved eastward,[
a] they found a plain in Shinar[
b] and settled there. 3 They said to each other, Come, lets make bricks and bake them thoroughly. They used brick instead of stone, and tar for mortar. 4 Then they said, Come, let us build ourselves a city, with a tower that reaches to the heavens, so that we may make a name for ourselves; otherwise we will be scattered over the face of the whole earth.
5 But the LORD came down to see the city and the tower the people were building. 6 The LORD said, If as one people speaking the same language they have begun to do this,
then nothing they plan to do will be impossible for them. 7 Come, let us go down and confuse their language so they will not understand each other.
8 So the LORD scattered them from there over all the earth, and they stopped building the city. 9 That is why it was called Babel[
c]because there the LORD confused the language of the whole world.
From there the LORD scattered them over the face of the whole earth.
So we see that nothing would be impossible for them, and they did not multiply across the earth, but stayed in one place. But that nothing would be impossible...they already had the knowledge of good and evil, and I believe God in his wisdom knew that man could not handle such knowledge of evil. Perhaps he knew if they lived together under one language (and one religion, Baal worship), they would fall to such depths of evil depravity, learn the hidden knowledge of such evil ways that the world would be doomed very quickly. I don't know, but I believe there is good reason behind God intervening at that time and it has to do with that statement that nothing would be impossible for them. It cannot mean "nothing GOOD would be impossible for them, for God is good, so it must mean "nothing EVIL would be impossible for them. Perhaps a king ruling his people with no freedom, like a Hitler or like the antichrist to come who will make a one world government, economy and religion and demand to be worshiped as God as many kings have done. This religion of Baal worship was the law of the land then and the people turned from the living God they knew to worshiping the creation, in this case the sun, and really Satan, as will happen when the antichrist demands worship or death. The world will eventually come together under the antichrist. The first time under Nimrod, God stopped, because he had other plans to take place first, like sending his son so the world may be reconciled freely to him first.