Is there a basis for the world state? If the liberals are right, there can be no agreement on fundamental values, so it has to be imposed from above. If the conservatives are right, there are objectively correct values, so there is a basis for bottom-up world state formation on the basis of the discovery of higher truths. The problem is one of countering ignorance.
In other words, for the world state to be possible, the liberal has to acknowledge the lack of universality of liberal values, and the conservative has to acknowledge the duty of universal values. In any case, the duty of both is to reconcile the view of the universality of value embedded in the core of each idea with their practical two-level division/relationship of politics and values that has emerged in a world of nation-states.
This reconciliation may be resolved (on the liberal side) by the dissolution of the politic-value distinction via the world-state or the destruction of the liberal state through libertarianism. In conservatism, it may be resolved via the universal spread of conservative values as the basis for political union or conversely, the protection of purity - the maintanence of purer communities through isolation, status structures, and other social or political methods.
