128 CHAPTER fouR ■ The InTernaTIonal SySTemFurthermore, the testing of systems theories is very difficult. In most cases, theo-
rists are constrained by a lack of historical information. After all, few systems theo-
rists besides some radical and cyclical theorists discuss systems predating 1648. In
fact, most begin with the nineteenth century. Those using earlier time frames are
constrained by both a poor grounding in history and glaring lapses in the historical
rec ord. Although these weaknesses are not fatal, they restrict scholars’ ability to gen-
eralize their findings.
Perhaps the most fundamental critique is the attention paid to one international
system in par tic u lar. Is not the idea of one international system really a Eurocentric
notion? Here, the critics have a valid point. The idea of an international system evolved
out of the state- centric, post- Westphalian world. In that world, the international sys-
tem consisted of sovereign Eu ro pean states that shared common pre- Westphalian tra-
ditions: the Roman Empire, which had imposed order and unity by force on a large
geographic expanse and used a common language, and the Christian tradition, as exem-
plified by the Catholic Church of the medieval era with its authority and law. From
those common social roots, the idea of the international system arose. Some scholars,
the so- called En glish school, call this system an international society, because it shares
a common culture that was a foundation for common rules and institutions. Accord-
ing to two of the principal architects, the scholars Hedley Bull and Adam Watson,
although the international system comprises a group of in de pen dent po liti cal commu-
nities, an international society is more than that. In an international society, the vari-
ous actors communicate; they consent to common rules and institutions and recognize
common interests. Actors in an international society share a common identity, a sense
of “we- ness.” Without such an identity, a society cannot exist.^15
Yet w ere there not international systems—or more accurately international socie ties—
beyond the Eu ro pean world? Perhaps those socie ties were based on other sets of rules
and institutions. For example, vari ous kingdoms flourished in China for centuries
before unification in 200 bce. Imperial China endured for 2,000 years, united
around a common culture that the Chinese thought was the center of the universe.
The Islamic peoples, too, shared a common identity as Islam spread across the Middle
East to Africa, Asia, and even Eu rope. That social identity can be seen in the belief in
the umma, or community of believers. The umma was symbolized by the institution of
the caliphate, the Islamic po liti cal authority, and was an identity that overrode tribe,
race, and even the state itself. That unity broke down in the division between Sunni
and Shia, a dispute over who was the rightful successor to the Prophet Muhammad.
Some advocate restoration of the caliphate as a renewal of Islamic civilization’s former
historical greatness, and the Islamic State proclaimed that restoration in 2014. Inter-
national relations scholars have often paid too little attention to non- European inter-
national socie ties.ESSIR7_CH04_106_131_11P.indd 128 6/14/16 10:05 AM