Bio-resources and empire building: What favoured the growth of Vijayanagara Empire?

Bioresources fuel the emergence of empires and civilizations; political will and social milieu can only catalyse the growth and establishment of the empires that are otherwise sustained by and only by, their biological resources. Emergence of Vijayanagara, as one of the richest empires in the world history, could be attributed to an opportunistic trading of its natural resources, viz. sandal, spices and diamonds, for the guns and horses. The military strength thus gained by the empire helped its growth and dominance over its rival regimes in the north. Similarly, its decline could be traced to the loss of control over, and reduced market value for, the same natural resources. History illustrates that those regimes that efficiently (and not necessarily sustainably) usurp the natural resources, gain political and military dominance over the competing regimes. For sustaining their own over-consumptive patterns of living, these super powers obviously turn to usurp resources from weaker regimes. The exploited poor regimes who are forced to live on limited (and sustainable) use of resources would continue to be weaker and be dominated by the super regimes. Till this vicious cycle is broken, the philosophy of sustainable use of resources continues to be an evasive strategy. Sustainable use of resources has to be a global mantra; else it would be a myth.