CEVAP:

The struggle between conservative monarchies and revolutionary movements had a profound impact on the nature of European politics in the 19th century. After 1815, European states were not only restored as monarchies but were also
committed to collectively preserve the monarchical nature of the international system.

To that end, they constructed a two dimensional collective security mechanism:

First, members of the Concert cooperated against internal threats from liberal or nationalist movements. The great powers, therefore, assumed the right to intervene in states threatened by internal revolutionary upheavals. As a result, the great powers suppressed revolutionary uprisings in Italy and Spain.

Second, the great powers kept France in check, since it was still considered a potential center for (and source of) revolutionary movements.