Complex sentence: Luxembourg had only received its recognition as a sovereign state, as a full member of the international community, in the course of the Second World War and at the cost of heavy sacrifice, which explains the government's reticence in renouncing part of its national prerogatives.
Split into simpler sentences: Luxembourg had only received its recognition as a sovereign state, as a full member of the international community, in the course of the Second World War and the cost of heavy sacrifice. This explains the government's reticence in renouncing a part of its national prerogatives.