In 1820, liberal movement spread from Spain and Portugal to Italy and Greece, Metternich then hastened to adopt the policy of intervention, despite the British protest. The Troppau Protocol as well as the decisions taken at the Congresses of Laibach and Verona was to his heart's content. Uprisings in Naples and Piedmont were crushed by Austria and that in Spain by France. From the point of view of the union of kings, the Congress System under Metternich's manipulations ensured domestic stability in the European states. In fact, in the long run, repression only increased the tension between the absolutism of the restored monarchies and the liberal revolutionaries, and in no way contributed to the maintenance of general peace.
The Greek revolt for independence from Turkey provided an occasion for Russia to advance her influence into the Balkans. Metternich had always feared Russian ascendancy in Lower Danube. In 1821, at Laibach, he dissuaded Alexander I from intervening against Turkey. Canning's policy of joint intervention by the Great Powers resulted in Greek autonomy. This alarmed Metternich for Greece might fell under Russian domination. He responded readily to Palmerston's bid to check Russian advance, and associated Austria with the final settlement of the London Conference of 1832 that ensured Greek independence not only from Turkey but also from Russia.
The July Revolution in France would not have been tolerated by Metternich, had it not been for the indifferent attitude of Britain. In August the Belgian followed, and the Dutch appealed to the Eastern Powers for help. But they dared not face the formidable Anglo-French force. The London Conference of 1832 guaranteed Belgian Independence and neutrality too. Metternich acquiesced in this settlement which brought the international crisis to a close, though he felt uneasy at the rise of liberalism in the West.
One of the results of the Greek revolt was the claiming of the reward by Mehemet Ali. Russia offered help to the Sultan in the hope of gaining control over the Straits. France, who supported Mehemet Ali, aimed at extending her influence to the eastern Mediterranean. Metternich was resolved not to see either Russia or France dominate in the Balkans, and thus acted along with Palmerston. The London Convention of 1841 cancelled Turkish obligation under the Treaty of Unkiar-Skelessi, thereby making Turkey less dependent upon Russia. The treaties of early 1841's restored the balance in the Near East, and Metternich saw that Austria was a part to all of them.
Mettenich's policy of intervention had been successful in Spain, Naples and Piedmont, and in an indirect sense in France too. In fact, repression was not helpful to peace, for it strained the internal tension to a breaking point and when the revolution broke out, they were all the more violent. Indeed, general peace was liable to break down whenever his policy of intervention was applied for it made certain that governments of absolute rulers were unaltered whenever there was a liberal uprising, and expeditionary forces to overrun a country was likely to cause friction among interested powers.
Obviously international peace in the years following 1815 was not the result of any deliberate policy of Metternich. An explanation for this striking feature could be that revolutions had served as a kind of substitution for wars. To sum up, Metternich can maintain peace in Europe to a certain extent at the beginning with his own system. However, in the later stage, owing to the growth of liberalism and nationalism and the desire of unification in both Germany and Italy, there was no longer real peace found in Europe. However, no one can deny that Metternich had contributed his effort to maintain the peaceful situation in Europe for the good of both Austria and Europe as a whole.