Ross Hassig's book is an excellent presentation of the history ofthe Aztec conquest of central Mexico, an amazing story ofrags to riches. It equals in drama the rise of Rome from an insignificant rural town and the rise of the United States from adependent set of colonies to world-system hegemony. The Aztecs were nomadic foragers who migrated into the valley of Mexico, a state-based world- system which had already seen the rise and decline of empires.

Occupying an island in a shallow lake surrounded by competing city-states, the Aztecs began their career as mercenary allies of the Tepanec empire. Their reputation as warriors grew with their successful conquests of adjacent city-states in alliance with the Tepanecs. Eventually they conquered their erstwhile allies and went on to create an empire which spanned the continent and extended far north and south of Tenochtitlan, the Aztec island capital.

The Aztecan rise to power took place in the following context. The valley of Mexico already contained a relatively high population density and an intensified horticultural form of production. Politically it was organized as a number of competing city-states that formed alliances in wars against one another and extracted tribute from dependencies. Earlier regional empires had dissolved into a decentralized "interstate system" that was structurally somewhat similar to the contemporary global polity except that it was composed of competing city-states rather than nation-states. The mode of production at the family and village level was primarily based on reciprocal kinship obligations, although some market exchange was also present. The overarching political economy was based primarily on the extraction of tribute (both prestige goods and basic goods) from dependencies through the use of political-military force, although there was also an important amount of market exchange of prestige goods among the separate states.

Within this context the Aztecs combined cultural and organizational features of the older core societies with elements of their own formerly peripheral society to create a new combination which gave them a comparative advantage in the valley of Mexico. When they began their career the Aztecs were a relatively unstratified group governed by a loose association of lineage heads. They soon created a nobility by intermarriage with the king of a nearby allied city-state who was allegedly descended from the Toltecs, an earlier imperial dynasty. As with other semiperipheral marcher states, the somewhat less stratified nature of Aztec society was an advantage in warfare (Chase-Dunn, 1988). Citizen soldiers who believe they have a stake in the collectivity are better warriors than conscripted peasants or paid mercenaries, and such a belief is easier to sustain when the differences between nobles and commoners are less extreme. Of course, the Aztecs, again like other successful conquerors, became more stratified within as their empire expanded. The acquisition of tribute made possible the expansion of the wealth of the nobility, and success in battle was an important means of upward mobility for commoners.

While the Aztecs rewrote their own history to provide a past linked with earlier empires, their version of Mesoamerican religious ideology also capitalized to some extent on their barbarian origins. In a system in which the perception of power was based largely on military prowess and fear of extreme punishment, it is an advantage to have a reputation for brutality.

Hassig's study focuses mainly on military organization, strategy and logistics. He is arguing against a number of recent interpretations of warfare in Mesoamerica which focus heavily on its connections with religious institutions (e.g.Conrad and Demarest 1984). War captives were the main source of human sacrifices, which, according to Aztec ideology, were necessary to appease the gods and to keep the universe functioning. Conrad and Demarest argue that the conversion of the existing Mesoamerican ideology ofhuman sacrifice into a "national" justification for continuous conquest and expansion represents the key innovation which made the Aztec success possible. For Hassig the Aztec intensification of sacrifice is was merely part of the strategy of rule by intimidation.

Hassig does not, however, argue that other innovations were more important for explaining the rapid rise of Aztec hegemony. He argues that the military weapons and strategies used by the Aztecs were not significantly different from those of their opponents. Hassig emphasizes the "rationality" and the cost-benefit logic of the Aztec strategies in terms of the goal of extracting tribute through the maintenance of the perception of superior military power. The Aztecan strategy of tribute extraction without direct control is compared with the more direct form of territorial domination theorized by Clausewitz. Hassig utilizes insights about the perception of power developed by Edward Luttwak (1976) in his study of Roman imperial strategy. He stresses the similarities of the underlying logic of the Aztecan strategy of imperial rule with other cases of successful empire expansion and maintenance. He argues that, once differences in the nature of imperial goals are taken into account, the logic of empire is much the same.

Hassig shows that the Aztec strategy was mainly one of demonstrating superior military power in order to extract tribute payments from local elites. The Aztecs did not usually attempt to reorganize the societies they conquered, but preferred a "hegemonic" form of indirect rule. Thus the maintenance of tribute payments depended on the "perception of power" as much as on direct coercion. This is very unlike the form of imperialism utilized by the Inkan empire, which was ideologically similar in some respects, but which used direct control over state lands and labor to mobilize "staple finance" (Johnson and Earle 1987 pp. 256-68).

The Aztecs used the "duck shoot" strategy to isolate strong foes before conquering them. This involves picking off weaker potential adversaries one at a time until more challenging opponents are isolated. Their empire was still expanding when it was conquered by the Spaniards, although it had already reached the size at which additional victories were becoming more costly. The limits of the expansion would have probably been reached by the end of the l6th century. Since maintenance of centralized control in such a system is based on the ability to keep providing additional spoils of conquest, collapse back into a decentralized interstate system would undoubtedly have followed the limits of expansion. The Spanish intervention, however, changed the nature and scale of the game, providing new means of extracting surplus and integrating Mesoamerica into a peripheral location within the Europe-centered world-system.

The Aztec empire emerged within a world-system in which state-based accumulation had become predominant and in which exploitation of peripheral regions by core states was a crucial aspect of the reproduction of political structures. This system differed from other somewhat similar systems in important ways, however. Other early state-based systems were also heavily dependent on hierarchical religions to legitimate state power, but the Aztec form of tributary accumulation through political/military terror placed extra emphasis on the importance of the state religion. It is notable that complex chiefdoms and primary states engage in human sacrifice to an extent not shared by either less stratified or larger and more complex societies (Davies 1984 p.213).

The psychology of sacrifice is important in all moral orders, and human sacrifice on some scale is known to almost all societies including our own. I am thinking not only of warfare, but of capital punishment. The Aztecs, however, intensified this aspect of Mesoamerican culture to a scale difficult to comprehend. Most scholars accept the estimate of 80,000 war captives sacrificed for a single temple dedication (Hassig 1988 p.121).

This kind of ritual was not simply a reflection of a system out of control, or the rational consumption of human flesh as a source of protein, as Marvin Harris's (1977) interpretation of sacrifices suggests. Rather such a religious hierarchy is an expanded instance of the symbolic demonstration of the power of the state to appropriate human life (rather than human labor time) in a situation in which the logic of "the perception of power" is based on terror and intimidation. Later states are just as objectively hierarchical but they do not rely so exclusively on hierarchical symbolic means to legitimate and enforce power relations. It is somewhat ironic that moral order in the form of an extremely hierarchical state religion is more important for these early states than it is for more complex societies in which commodity economy, bureaucratic organization, and legal structures are the institutional forms which support inequality.

Hassig's book is an excellent contribution to the sociology of military organization and strategy. His explanation of the course and results of the Spanish conquest is a convincing application of his theoretical approach. The book would have benefited from a somewhat more consciously comparative perspective, not only with other early state-based world-systems and empires, but also with Hassig's own earlier work on the nature of the Mesoamerican economy (Hassig 1985). It would be helpful to understand the interconnections between the strategy of tribute gathering and the activities of the pochteca (long distance merchants). Hassig details the military services of the pochteca as spies, but he does not tell us how their trade-based accumulation activities were linked to the Aztec state, or what role such linkages may have played in this apparently most tributary of modes of production. His other book (Hassig 1985) makes it clear that such linkages were important. What is missing here is an analysis of the way in which returns from trade and tribute were combined in the financing of the Aztec state, and the role that trade and unequal exchange may have played in the logic of imperial expansion and accumulation.

These are important questions not only because we need to sort out the general relationships between world-systems and modes of production but because it is likely that the earlier empires in the valley of Mexico were based much more on control of trade routes through the establishment of settler-colonial outposts rather than on the direct extraction of tribute. Was the Aztec empire different in the extent to which it relied on extraction of tribute in comparison with the empires of Teotihuacan or the Toltecs?

If this is the case does the reason for this shift have something in common with the sequence which occurred in Lower Mesopotamia, in which the early Uruk expansion was based primarily on trade with relatively unstratified societies (Algaze 1989), whereas the later Akkadian empire was much more based on the extraction of tributes? And might the explanations for these sequences be similar? It is unfair to fault Hassig for failing to address questions which are admittedly beyond the theoretical perspective within which he is working. His book is fascinating reading for students of imperialism and military organization, and is fertile matter for those who want to compare earlier, smaller world-systems to our own.