National political parties have a mandate to defend the interests of the nation that they represent – even if they run for trans-national elections (such as the elections to the European Parliament). They reason and act at national scale, and share the powerlessness of small-scale political action – or the unaccountability of inter-governmental negotiations when attempting to build loose federations (such as the existing "Internationals").
We do not want to end up in the same powerlessness as the existing national political parties.
The CosmoPolitical Party is precisely created to overcome the weaknesses of national politics, at their root: the mismatch between the scale of political action, and that of the phenomena upon which political action is needed. This is why our organisation is trans-national from inception, and will not build national branches.
By setting up a new, trans-European structure, we start small. But we give ourselves the capacity to reach in the longer term an effectiveness much larger than that of any existing national political party. This is why we don’t join them.