That is a complete non-sequitur. Free societies need to oppose those who would destroy their freedoms. How does that have any bearing whatsoever on whether free societies can be established?

> need to oppose those who would destroy their freedoms

Of course no-one can argue against it if you re-state it like that. But the paradox goes much further: "Popper asserted that to allow freedom of speech to those who would use it to eliminate the very principle upon which they rely is paradoxical."

And this means that free society cannot be established because....?

Tolerant, not free. The terms are not interchangeable.

The paradox implies it because if the ideas of tolerance are so fragile, that even in a majority tolerant society, intolerant ideas present such a threat as to consider sacrificing even free speech, then how could they have ever come to dominate in the first place?