The
modern state system is an association among sovereign and equal powers. It was
born with the peace treaty of Westphalia in 1648 which ended the thirty years
war in Europe.  Scholars commonly
designate 1648 as the time the state system began to take on its modern
form.  Thereafter, European rulers
refused to recognize the authority of the  
Roman Catholic Church, replacing the previous system of papal government
with geographically and politically separate state which recognized to
authority above them. The treaty of 
Westphalia came with notable changes-England France, Sweden, Holland and
Spain became  independent and national
states.1
 The  newly
independent  states were all given the same
legal rights: territorial indivisibility; 
freedom  to conduct foreign
relations and   negotiate treaties with
other states;  the authority to
re-established  whatever form of
government they thought  best to  rule their  
own population.
In 1861, the state of Italy was proclaimed, while the
Germans achieved unification in 1871. 
In the Balkans, the collapse of the Ottoman Empire
gave way to independence among slaves in the 19th and 20th centuries. In the
Western hemisphere, America had gained independence in 1776. In 1822, Brazil
declared here independence of Portugal.
In the Far East, Japan emerged from feudalism 1867-68
with the collapse of the Shogunate. When World War 1 fell outside the European
continent.  After the war and the peace
treaties with those defeated, only USA and Britain could be described as major
powers, (Wittkpof 1978:74 )
Evolution of International Society  
“International society 
stands for  relations between
politically  organized  human groupings which occupy distinctive  territories and enjoy and exercise a  measure of 
interdependence  from each other”.2  it is a 
political  community which  is sovereign (not under any higher political  authority). In international relations
parlance, such communities are regarded as states. They usually consist   of: 
a.      Permanent population 
b.      Defined territory 
c.      A central 
government, and 
d.      Must  be
independent of all other states  with the
same status3 
Hedley Bull summarizes the foundation of
international  relations as the existence
of states or  independent  political communities each of which possesses
a  government and  asserts sovereignty  in relations to particular  portion 
of  the earth’s  surface  
and a particular segment of  human
population.4   
The Emergence of Modern State System 
The first historical manifestation of international
society was in grace. It  comprised a
large number of  city  states. 
Geographically located at the lower Balkan peninsula the  Adriatic and the Aegean seas.  
They had a common language, ancestry, religion and way
of life which distinguished them from those of their neighbours whom they
called barbarians. That is those who did not speak Greek or Latin.  Sparta, Corinth and Athens were Greek
city-states but Athens was the most popular. 
They constituted the first international society in Western history. It
is  important to state that Greece was
not a state.  The society   consisted of city-states which were  for all intents  and purpose independent of each other.
The city –state maintained relations but the identities
of each was preserved through ceremonies, cults, oracles,  but 
political arrangements were the same.
The  city-states
consulted the oracles at Delphi  in  resolving anything in dispute. They equally
evolved  such  special political   vocabularies as  reconciliation, truce, alliance peace, etc.
they did not establish resident diplomatic institutions. That were an invention
of Italian renaissance. The  ancient
Greeks did not articulate international 
law   because they could not
conceive of the city states as having 
rights and duties in relation to 
other city-states.5 The 
ancient  Greek city  states were politically self contained,
their  international  society 
was cultural/.religious rather 
than legal  / political.5
            Though the ancient Greeks  did not conceive international law in
practical terms, they  nevertheless  recognized that certain principles ordained  by the gods 
or dictated by practical reality should govern the conduct of relations
between the city-states.
The ancient Greeks constructed an international
society which survived in the face of hegemonic empires like Persia, Rome
and  Macedonia. The first  modern 
international society based on large-scale territorial states  came into 
existence a little later in north western Europe out of which  the global international society has evolved.
The 
state 
The state is any body of people occupying a
definite  territory and politically
organized under one government6. 
The terms state, government and nation differ in meaning. A  government is the established form of
political  organization  of a state. A nation may be a body of
inhabitants occupying a   definite
territory with a common culture. A “nation”  
may also mean any aggregation of people having like institutions and
customs and a sense of social 
homogeneity and mutual 
interest”.  A nation may extend
beyond the borders of a  particular
state. State, nation and country are used 
interchangeably by  writers for
choice of words not necessarily  because
they mean exactly the same thing. 
States have vast differences which include size,
population,  culture, government ,
military strength, etc.   Through
international law, all states are equal and sovereign,  but in actual fact there are many
inequalities and many degrees of 
dependence among states.  For
instance, the  annual budget  of the city of New York is larger than that
of the states of the world.
            The national budget of India with a
population of more than half a billion is smaller than that of Britain which
is  less 
than 19th  as  many people. States also differ
significantly   cultures,  religion, language, history, tradition,
ethical  codes social patterns, economic
and political ideologies.  A state may
operate parliament or military, some governments are dictatorial and honest.
Others are democratic and corrupt, etc.  
In international affairs, the most common way
classifying states is with a re-course to national power “great power” or  “major powers”  and “small powers”, world power,  super powers, middle powers and powers
of  uncertain  status. The United States of America is a
world power in terms of worldwide commitments and extra-ordinary  military 
strength. 
During World War II, 
which involved Japan, Italy and Germany on one side and USA, great
Britain,  France and Russia on the other,
France was easily overrun, but  with  a combined effort of Russia, great Britain
and USA,   Nazism  in  
Germany was utterly destroyed, 
fascism in Italy, and military 
fascism and emperor  system in
Japan were equally  crushed  japans attack 
on the pearl  harbour in  1941 
forced the USA  to  join the war on the side   of allied powers.  At the end, USA  and 
Russia emerged as world powers.
In its broadest historical perspective, the
present  state system is explained by
Aristotle’s  celebrated observation  that man is by nature a political animal.
This means that   at all  stages of development people have needs and
wants which  they cannot realize alone.
Hence, they form social groups. Such groups 
differ greatly in their  nature and
scope  according  to 
circumstances but they 
invariably  strike a  host 
of   organizational problems
pertaining to the  structure  of the group and also its relationship with
other groups,  the  equivalent of modern international  relations. They  had the 
problems of delimitation and inding the size best  suited 
for  the  groups. 
Plato and Aristotle discussed 
it  in their analyses of  the Greek city states.  The first large scale politically  organized states and state systems of which
there are records  developed about
5000BC  in the Nile valley, the Tigris
and  Euphrates and later in  the great rivers of China.  This development was not due  to 
accident but to a social need common to all these areas. In these areas,
states became  enmeshed in networks of
interstate relations alternating  between
the two patterns of separate warring and cooperating  units and of great empires imposed on them.
These political systems usually led by civilizations were fluctuating in their
boundaries but were geographically fairly segregated from one another,  early development of a degree of culture and
political  coherence. The  medieval Christian commonwealth  successfully preserved the idea of unity
through the intuitions  of the church and
the universities. The medieval order 
eventually crumbled under the impact of the  renaissance and the reformation. The  local princes who rose to political  prominence through the acquisition of
territory became  immersed in
religious  wars,  fighting for their creeds abroad  and trying to ensure their complete sway  at home Machiavelli  rightly observed that modern states are  based 
on power but religious origin must not be neglected.  Religious 
forces did  not  disappear 
from politics completely but in form of national churches,  generally adapted themselves to the  new units.
The system of sovereign territorial state was formally
established by the peace treaty of Westphalia in 1648.  It was  
first limited to Europe. Gradually, however, European states extended
their rule over other  continents
which  they  considered fair game for their expansion.
They  thus  molded oversea  territories within  their empires.