Complete the following sentence: The success of the military revolution at Naples seriously alarmed the powers of the Holy Alliance, who feared that it might spread to other Italian states and so lead to a general European conflagration. 1820<unk> The Troppau Protocol was signed by Austria, Prussia and Russia, although an invitation to Ferdinand to attend the adjourned
Congress of Laibach (1821) was issued at which he failed to distinguish himself. ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Metternich had no difficulty in persuading the king to allow an Austrian army to march into Naples "to restore order".<unk> Metternich had no difficulty in persuading the king to allow an Austrian army to march into Naples "to restore order".<unk> Metternich had no difficulty in persuading the king to allow an Austrian army to march into Naples "to restore order".