Westphalia was signed by approximately 150 European ‘territorial
authorities’, but at that time there were only six or seven modern states. After the
Napoleonic Wars, at the beginning of the ‘imperialist age’ (1840–1914), this
number increased due to the independence of American states, and at the end of the Second World
War the UNCharter was signed by 50 independent states.
It was in the second half of the twentieth century that the inter-state system expanded more
rapidly. Today there are almost 200 sovereign states with a seat at the UN