So, by applying your logic, any State which happens to be established has the right to shut up everyone expressing an opinion which undermines it. All the Kings and Emperors throughout history were right to kill their critics, since after all those states were based on the ideas of Monarchy. The Catholic Church has the right to silence its critics in Vatican City. Turkey has the right to crush religious expression which threatens secularism, since the Turkish state is based on secularism. The French state has the right to prevent Muslim children from wearing the hijab in schools....after all, that threatens the secular basis of the French state. The state of Israel has the right to imprison people who question or deny the Holocaust.
I, on the other hand, reject all these. None of these states have the right to prevent freedom of speech, even if freedom of speech weakens the state.
What you have said is the same misguided excuse that is always used to justify and defend tyranny: "Free speech undermines the state". Yes, sometimes it does. If your State is so fragile, or so easily criticized that the expression of critical opinion undermines it, and perhaps alters it, then it should be altered.