In strict legal consideration, the  states of  
the international  system are said
to be equal one to another. This  is  what is normally referred   to as 
“sovereign equality”  as  provided for in  article 
2 of the charter of the united nations  in reality, however, vast inequality exists
among the states  of the international
system.
As  already
pointed out,  differences or inequality
could be observed in various areas 
ranging from population  size,
geographical expanse, natural resource endowment,  economic buoyancy, patriotic zeal and
nationalism;  to military   capability 
and national  morale.  In this section, we are concerned with
categorizing and   classifying the state
system in the power   political context.
This  presents a
number of problems. As was noted during the consideration of  national power, the power  position of a state is the result  of many variable- tangible  and intangibles. However,  certain general yardsticks can be  employed in determining the various cadres
into which states may be categorized in their power index.
Before attempting the categorizations, it is necessary
to determine how many such categories exist. 
States  have been classified
into  great powers or major powers and
small powers or lesser powers, we do also speak of  “world 
pwers”,  “super powers”,  “middle powers” and  what Palmer and Perkins refer to as ‘powers
of uncertain status’.22 
These  classifications would l
appear more historical than 
contemporary. The state system in the contemporary period  (at least since 1945)  can be delineated or categorize into
four  main groups –super powers, great
powers  or major powers,  medium powers 
and small or nominal powers.   
In deciding which state falls under which category ,
certain  are usually used. This  brings us back to the national power  paradigm. Thus  the ability/inability  of a state 
to  impose its will with a
credible measure of coercive sanction to compel compliance  from the greatest number  of states and non-state actors in the
international environment ,  remains a
clear determinant to its positioning in the various categorizations mentioned
above.
Using the above criteria, it is  thus axiomatic that the  super powers are at the apex of a pyramidal
configuration of   the  states system in the power political context.
This  is 
because they are well –placed and endowed  with 
requisite  national power to
compel compliance from the greatest 
number of states to either do their will or refrain from openly opposing
them in international political arena. 
Some writers refer to super power   
as those states that had or have ‘worldwide possessions and interests”.
This is not saying anything different from our previous contention, retaining
the ability to be considered as have worldwide possessions and interests is a
function of a states national power.
Between 1945 and 1989, the world played host to  two super powers – the untied states of
America (USA)   and the  Union of Soviet socialist republics
(USSR).  In the   period 
before 1945, the  term  super power had not come into general  use, it was not   that there were no powers that came close
to  meeting the  general requirements of that status,  commentators 
of that period preferred to refer to them as ‘world powers”.  Colonial great Britain, France, Portugal,
Belgium, Spain, including the Netherlands could be included in this
categorization in descending order of importance
A more appropriate terminology and one ‘sanctified by
long historical usage’ is the great power or major power.  The nation –building careers of Otto Von
Bismack  in  Prussia 
and Carvour in Italy, saw   the
emergence of Germany and  Italy  as 
great powers.  The duo joined
great Britain, France,  Russia and later
Japan in the rank of the great powers of the 19th century international
system.
With the advent in 1945 of the UN system the  international system  began to experience some  metamorphosis –the  two super powers (already referred to )  fused with three other powers –France ,
Britain  and china  to form the five permanent members of the
security council with  vetores or casting
vote.  Thus  as part of the “dividends”  of their roles in World War II, Germany and
Japan lost their status as great pwers of the post –war international system.
This was, of course, a direct consequence of the victory of the allies against
the axis powers in World War II. It is necessary to note that Germany
effectively joined the rank for the great power following its victory in the
Franco-Prussian war of 1871. In the same vein, Japan almost completely eclipsed
Russia’s claim to great power  status
following its decisive  victory in
the  1904/05 Russia-Japanese war.
While  one can
declare with   some measure of confidence
that in the  19th century
international system,  victory in major
conflicts  remained one of the
clearest  determinants in upward mobility
of states on power categorizations. The opposite also remained a sure way of
losing such status, the contemporary international system does not appear to
have shown any marked departure from  the
above scenario. It is obvious, for instance, that if Iraq had   defeated the world coalition thrown against
it, thereby making   good its claim or  Kuwait as its 
19th  province, it
would have emerged not only a major 
power  within the Middle-East , but
more importantly, a major world player in energy politics and  the armaments that  would 
be needed to advance and protect 
its  interests ion those
areas.  The fluidity of power and the
vicissitudes that attend its deployment and management make precise
categorizations of states in the power political context problematic. A great
power today could became a  medium or
nominal  power tomorrow, and vice  versa.
The situation became peculiarly hazy following the
post world war ii emergence of the US and the USSR as super power as indicated
earlier. With  the  emergence of the  untied states as the sole superpower
following the  diminution of soviet power
in 1989,  the situation appear a bit  clearer, the seven most industrialized  states – Britain, France, Germany, Japan,
Italy, U,S,A Canada  could be considered
as   the great powers  of the contemporary era.  The medium  
powers would then be the regional influential.  That is 
those states whose influence is preponderant in their various  regions –India, Pakistan in West Asia ; Japan
and China in North Asia, Indonesia, South East Asia,  Brazil, 
Argentina  Chile, South America,
Israel ,  Saudi Arabia, Middle East;  Nigeria, West Africa, Egypt, North Africa,
South Africa ,  Southern Africa; Kanya,
Tanzania, East Africa ; etc. 
The small 
powers or normal state have  been
described as “powers  with the means of
defending only limited interests”.23 With this categorization, small
states  will   include all the state of the international
system except the  great and medium
powers, perhaps we may state for purposes 
of emphasis that most of the categorization indicated above  are made 
purely for analytical purposes 
and they  do not   in 
any  way represent it closed  case 
of taxonomical classification of the entire state system in their power
index.